Reasoning backward and forward

Birthright citizenship and the horseshoe

On January 20, 2025, President Trump issued an Executive Order declaring that a person is not a U.S. citizen “(1) when that person’s mother was unlawfully present in the United States and the person’s father was not a United States citizen or lawful permanent resident at the time of said person’s birth, or (2) when that person’s mother’s presence in the United States was lawful but temporary, and the person’s father was not a United States citizen or lawful permanent resident at the time of said person’s birth.” The lawsuit count on this Executive Order has hit ten, with four preliminary injunctions so far.

I am diffident about writing on this issue, both because there has already been abundant commentary and because my view aligns with the conventional wisdom: the Executive Order is inconsistent with the Fourteenth Amendment. Still, there is enough storage space on the Internet for one more think-piece.

In this post I’ll offer my take on why the Fourteenth Amendment confers birthright citizenship. I’ll also discuss what I see as the deeper philosophical issue at stake. Should judges decide legal questions by applying neutral principles and following the law where it leads, or by reasoning backward from what they perceive as the just conclusion? Under a neutral-principles approach, the pro-birthright-citizenship position is unassailable. Under a reasoning-backward approach, the anti-birthright-citizenship position is at least possible.

The Drive for Five

It seems weird that the child of an illegal immigrant or a non-resident would become a U.S. citizen merely by virtue of being born on U.S. soil. But weird as it may be, the legal case for that position is exceptionally strong.

There are five primary arguments for birthright citizenship:

1. It’s consistent with the Fourteenth Amendment’s text.

2. It’s consistent with British common law.

3. United States v. Wong Kim Ark, 169 U.S. 649 (1898), essentially answers this question.

4. We’ve been doing it this way for a long time.

5. Statements by members of Congress during the debates over the Fourteenth Amendment indicate that they understood it to confer birthright citizenship.

Let’s go through those one by one.

1. The text

The Fourteenth Amendment says this:

All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside.

Are the children of illegal immigrants and non-residents “subject to the jurisdiction” of the United States? In ordinary English, yes. The ordinary meaning of “jurisdiction” is “authority,” and the children of illegal immigrants and non-residents are most certainly subject to United States authority. If they commit a crime, they go to jail.

Might “jurisdiction” have some kind of special lawyerly meaning that differs from its ordinary meaning? As someone who traffics in lawyer-ese for a living, I can confirm that the answer is no. When we talk about a court having “personal jurisdiction” over a defendant, we mean that the court has authority over the defendant.

This is not a novel argument. If you have the misfortune of reading a Twitter/X debate on birthright citizenship, you will often find this point in the Most Relevant Reply. By contrast, the contrary textual argument—that “jurisdiction” means “at least one of your parents has a green card”—is not so easy to fit into 280 characters.

Simple arguments are good! It should be cause for celebration when people can understand what the Constitution means simply by reading it. There should be a strong presumption that the plain-English interpretation of a constitutional provision is correct.

2. The common law

The Supreme Court frequently interprets the Constitution by looking to the British common law, and the common law strongly supports the birthright-citizenship position. At common law, if a child was born on British soil, and was subject to the King’s authority, the child was a British citizen. This included the children of foreigners who were merely passing through.

What does the “King’s authority” mean? Well, if a foreign diplomat had a child on British soil, the child wouldn’t become a British citizen, because under principles of international law, the diplomat wasn’t subject to the King’s authority even while physically present in Britain. A version of the same principle survives today; it’s why diplomats don’t pay parking tickets. Likewise, if an enemy invaded Britain and was occupying the territory, the occupier’s children wouldn’t become British citizens because the territory would be under the authority of the occupier, not the King. So the formula was: Born in Britain + Subject to King’s Authority = British Citizen.

So we have a happy confluence of arguments. The plain-English interpretation of the constitutional text—“jurisdiction” equals “authority”—also is a perfect match to the common law, in which citizenship turned on authority. This is exceedingly strong evidence that this interpretation is correct.

3. The Wong Kim Ark case

In the late 19th century, people born in China were banned from becoming U.S. citizens. Wong Kim Ark was born on U.S. soil to two Chinese nationals. In United States v. Wong Kim Ark, 169 U.S. 649 (1898), the Supreme Court held that he was a natural-born U.S. citizen.

The Wong Kim Ark decision is long and drags on, but at core, the Court pretty much relies on the reasoning I just gave. The Court says that the Constitution “must be interpreted in the light of the common law, the principles and history of which were familiarly known to the framers of the constitution.” The Court then interprets the word “jurisdiction” in line with the common-law rule: “The fundamental principle of the common law with regard to English nationality was birth within the allegiance—also called ‘ligealty,’ ‘obedience,’ ‘faith,’ or ‘power’—of the king. … But the children, born within the realm, of foreign ambassadors, or the children of alien enemies, born during and within their hostile occupation of part of the king’s dominions, were not natural-born subjects, because not born within the allegiance, the obedience, or the power, or, as would be said at this day, within the jurisdiction, of the king.” The Court also notes that prior to the Fourteenth Amendment, “all white persons, at least, born within the sovereignty of the United States, whether children of citizens or of foreigners, excepting only children of ambassadors or public ministers of a foreign government, were native-born citizens of the United States.”

The Court distinguishes the 1884 case of Elk v. Wilkins, in which the Supreme Court held that Indians were not entitled to birthright citizenship. The Court explains that “the Indian tribes, being within the territorial limits of the United States, were not, strictly speaking, foreign states, but were alien nations, distinct political communities, the members of which owed immediate allegiance to their several tribes, and were not part of the people of the United States.”

Importantly, Elk is consistent with interpreting “jurisdiction” to mean “authority.” At the time of the Fourteenth Amendment, Indians actually weren’t subject to the United States’ authority, or at least not completely. As the Wong Kim Ark Court emphasizes, the Constitution, as originally enacted, excluded “Indians not taxed” from the count of “free Persons” for purposes of congressional apportionment. This reflected that the United States literally wasn’t exercising authority over Indians, at least for purposes of taxation. This was so both for philosophical reasons—the Indians had their own leaders and never agreed to pay taxes to European immigrants—and practical reasons—in the nineteenth century, American authorities couldn’t and didn’t exercise law-enforcement authority in many areas occupied by Indians.

But the Court is emphatic that Elk doesn’t extend to non-Indian foreigners:

The decision in Elk v. Wilkins concerned only members of the Indian tribes within the United States, and had no tendency to deny citizenship to children born in the United States of foreign parents of Caucasian, African, or Mongolian descent, not in the diplomatic service of a foreign country.

And so the Court reaches the following conclusion:

[A] child born in the United States, of parents of Chinese descent, who, at the time of his birth, are subjects of the emperor of China, but have a permanent domicile and residence in the United States, and are there carrying on business, and are not employed in any diplomatic or official capacity under the emperor of China, becomes at the time of his birth a citizen of the United States.

I promise you the Supreme Court did not reach this conclusion because of some kind of proto-wokeness. Wong Kim Ark was decided two years after Plessy v. Ferguson, which upheld racial segregation in Louisiana; every Justice in the Wong Kim Ark majority was also in the majority in Plessy v. Ferguson. Also, Wong Kim Ark was decided five years after Fong Yue Ting v. United States, a brutal decision upholding a federal statute under which any person of Chinese descent would be deported unless he could prove, based on the testimony of “at least one credible white witness,” that he entered the United States legally. (Reasoning: non-white witnesses have “loose notions … of the obligation of an oath.”) In short, the 1898 Supreme Court’s anti-woke credentials were absolutely sterling. The Supreme Court upheld birthright citizenship because the Constitution’s text and history left it little choice.

Opponents of birthright citizenship emphasize that Wong Kim Ark’s parents entered the United States legally and had a “permanent domicile and residence in the United States.” Thus, they contend, the decision doesn’t cover the children of illegal immigrants and non-residents.

But that’s not a basis to distinguish Wong Kim Ark. Wong Kim Ark is incredibly emphatic that the sole exceptions to the birthright-citizenship rule are Indians and the children of diplomats and occupiers. For example:

The real object of the fourteenth amendment of the constitution, in qualifying the words ‘all persons born in the United States’ by the addition ‘and subject to the jurisdiction thereof,’ would appear to have been to exclude, by the fewest and fittest words (besides children of members of the Indian tribes, standing in a peculiar relation to the national government, unknown to the common law), the two classes of cases,—children born of alien enemies in hostile occupation, and children of diplomatic representatives of a foreign state,—both of which, as has already been shown, by the law of England and by our own law, from the time of the first settlement of the English colonies in America, had been recognized exceptions to the fundamental rule of citizenship by birth within the country.

And it’s not as though the Court wasn’t thinking about non-residents and illegal immigrants. On the subject of non-residents, the Court approvingly quotes the common-law rule that birthright citizenship applies “whether the parents were settled, or merely temporarily sojourning, in the country, was an English subject.” The dissent is even clearer about this:

The English common-law rule recognized no exception in the instance of birth during the mere temporary or accidental sojourn of the parents. As allegiance sprang from the place of birth regardless of parentage, and supervened at the moment of birth, the inquiry whether the parents were permanently or only temporarily within the realm was wholly immaterial.

And on the subject of illegal immigration, the Court goes on for several paragraphs about how Congress has the total plenary authority to deport illegal Chinese immigrants for any reason whatsoever. For example, it says: “The right of the United States to expel such Chinese persons was placed upon the grounds that the right to exclude or to expel all aliens, or any class of aliens, absolutely or upon certain conditions, is an inherent and inalienable right of every sovereign and independent nation, essential to its safety, its independence, and its welfare.”

Yet immediately after expressing passionate support for the deportation of illegal Chinese immigrants, the Court solemnly intones: “The fourteenth amendment, while it leaves the power, where it was before, in congress, to regulate naturalization, has conferred no authority upon congress to restrict the effect of birth, declared by the constitution to constitute a sufficient and complete right to citizenship.” There’s no way to read this opinion as somehow leaving open the status of the children of non-residents and illegal immigrants.

Moreover, let’s take a step back. When we’re trying to figure out whether the Fourteenth Amendment confers birthright citizenship, we’re not trying to figure out whether birthright citizenship is a good idea. We’re trying to figure out what the word “jurisdiction” means. The pro-birthright-citizenship position has a coherent interpretation: “jurisdiction” means “authority.” Whereas there’s no way to gerrymander the word “jurisdiction” to include people like Wong Kim Ark whose parents were residents but ineligible to be citizens, but exclude people whose parents were non-residents or illegal immigrants. Maybe there’s a philosophical reason why we should draw the line this way, but that’s just not what “jurisdiction” means. You’ll never find the word “jurisdiction” being used this way in any other context; this definition of “jurisdiction” is invented for purposes of the birthright citizenship dispute.

Keep that analysis in mind as we look at the Wong Kim Ark dissent. The dissent says that a person isn’t entitled to birthright citizenship unless he’s completely subject to United States jurisdiction, and defines “completely subject” in the following way:

To be ‘completely subject’ to the political jurisdiction of the United States is to be in no respect or degree subject to the political jurisdiction of any other government.

And so why is Wong Kim Ark not a U.S. citizen, in the dissent’s view? The dissent opines that dual citizenship is not a thing:

Double allegiance, in the sense of double nationality, has no place in our law, and the existence of a man without a country is not recognized.

The dissent explains that all persons born in China are Chinese citizens for life, whether they like it or not:

Generally speaking, I understand the subjects of the emperor of China—that ancient empire, with its history of thousands of years, and its unbroken continuity in belief, traditions, and government, in spite of revolutions and changes of dynasty—to be bound to him by every conception of duty and by every principle of their religion, of which filial piety is the first and greatest commandment; and formerly, perhaps still, their penal laws denounced the severest penalties on those who renounced their country and allegiance, and their abettors, and, in effect, held the relatives at home of Chinese in foreign lands as hostages for their loyalty.

This means that all children of people born in China are Chinese citizens for life, whether they like it or not:

I take it that the children of aliens, whose parents have not only not renounced their allegiance to their native country, but are forbidden by its system of government, as well as by its positive laws, from doing so, and are not permitted to acquire another citizenship by the laws of the country into which they come, must necessarily remain themselves subject to the same sovereignty as their parents, and cannot, in the nature of things, be, any more than their parents, completely subject to the jurisdiction of such other country.

Thus, because dual citizenship is a contradiction in terms, and the children of Chinese citizens are themselves Chinese citizens, they cannot possibly be natural-born U.S. citizens.

This, of course, would imply that people of Chinese descent can never be natural-born U.S. citizens, no matter how many generations their ancestors have lived in the United States. The dissent says the quiet part out loud:

I am of opinion that the president and senate by treaty, and the congress by legislation, have the power, notwithstanding the fourteenth amendment, to prescribe that all persons of a particular race, or their children, cannot become citizens, and that it results that the consent to allow such persons to come into and reside within our geographical limits does not carry with it the imposition of citizenship upon children born to them while in this country under such consent, in spite of treaty and statute.

OK boomer! But I’ll give the dissent one thing: at least it’s offering what can reasonably be described as an interpretation of the phrase “subject to the jurisdiction.” Now that Wong Kim Ark is on the books, however, the anti-birthright-citizenship position requires “subject to the jurisdiction” to mean one thing for the children of residents who are ineligible for citizenship (i.e., Wong Kim Ark himself) and another thing for the children of non-residents and illegal immigrants. That’s not a genuine interpretation; it’s just treating the word “jurisdiction” as an empty vessel to be filled with whatever you want it to mean.

4. We’ve been doing it this way for a long time.

Ever since Wong Kim Ark was decided, the government has always assumed that the children of illegal immigrants and non-residents are citizens.

There’s a school of thought that says: “If people have thought for a long time that a constitutional provision carries a particular meaning, we should stick to that meaning.” I’m not going to give a bullet-pointed list of justifications for this school of thought. That is why God invented AI.

Whatever you may think of this view, it is influential among the Justices. In CFPB v. Community Financial Services Association, Justice Kagan, joined by Justices Sotomayor, Kavanaugh, and Barrett, wrote a concurrence observing that “‘[l]ong settled and established practice’ may have ‘great weight’” in interpreting constitutional provisions about the operation of government.” I’m not sure whether to treat the “long settled practice” as dating back to 1898 or some earlier point. But even if the right date is 1898, we were still using flip-phones back then. It’s a long time ago.

5. The debates

Members of Congress publicly debated the various provisions of the Fourteenth Amendment. The debates are interesting to read; to my eye, the Congressmen were far more eloquent then than they are now, although that is a low bar. You will find a lot of misleading partial quotations of the debates on the Internet, so if you’re interested in this topic you have to read the original source material. Like an animal!

There is only so much juice you can get out of the debates. It’s basically legislative history, which modern Supreme Court opinions tell us we should ignore. Also, the Congressmen spend a lot of time arguing with each other about what various provisions mean, so the debates are often inconclusive.

Still, there are some interesting nuggets in there. As far as I can tell, all of the debaters assumed that the U.S.-born children of non-diplomat foreigners would be U.S. citizens. Senator Wade thinks so:

Mr. FESSENDEN. Suppose a person is born here of parents from abroad temporarily in this country.

Mr. WADE. The Senator says a person may be born here and not be a citizen. I know that is so in one instance, in the case of the children of foreign ministers who reside “near” the United States, in the diplomatic language. By a fiction of law such persons are not supposed to be residing here, and under that fiction of law their children would not be citizens of the United States, although born in Washington. I agree to that, but my answer to the suggestion is that that is a simple matter, for it could hardly be applicable to more than two or three or four persons; and it would be best not to alter the law for that case.

So Senator Wade is saying: “It’s not a problem that the children of foreigners will get birthright citizenship, because there’s a legal fiction that the children of diplomats actually aren’t physically present in the United States, and anyway this happens rarely.” His underlying assumption is that under the Fourteenth Amendment, foreigners born on U.S. soil, other than the children of diplomats, will be citizens.

And then there’s this statement from Senator Howard:

Mr. HOWARD. …This amendment which I have offered is simply declaratory of what I regard as the law of the land already, that every person born within the limits of the United States, and subject to their jurisdiction, is by virtue of natural law and national law a citizen of the United States. This will not, of course, include persons born in the United States who are foreigners, aliens, who belong to the families of ambassadors or foreign ministers accredited to the Government of the United States, but will include every other class of persons.

I’ve seen some people on the Internet interpret Senator Howard to be saying that the children of “foreigners”—all foreigners—AND “aliens, who belong to the families of ambassadors or foreign ministers” won’t be citizens. But that doesn’t make sense. Otherwise he would have just said “foreigners” and there would have been no need to mention “ambassadors or foreign ministers.” To my eye, he’s saying that there’s a narrow exception to birthright citizenship for families of ambassadors or foreign ministers. Also, he makes a statement later in the debate opposing discrimination against Chinese nationals that, in context, makes clear that he’s assuming that the U.S.-born children of Chinese nationals will become U.S. citizens.

One more note. Multiple debaters opine that the children of Indians won’t become citizens because the United States lacks authority over them. For instance, Senator Trumbull says: “We have had in this country, and have today, a large region of country within the territorial limits of the United States, unorganized, over which we do not pretend to exercise any civil or criminal jurisdiction, where wild tribes of Indians roam at pleasure, subject to their own laws and regulations, and we do not pretend to interfere with them.” In other words, the debaters understand “jurisdiction” to conform to its natural meaning: “authority.”

In summary, there are numerous statements in the debate that support the birthright-citizenship position, and I don’t see any statements pointing in the other direction.

The curveballs

There are two other issues in the mix.

The first is the living Constitution. Vice President Vance opined: “Just because we were founded by immigrants, doesn’t mean that 240 years later that we have to have the dumbest immigration policy in the world.” I have seen similar arguments that birthright citizenship is so unbearably dumb that it just doesn’t matter what “jurisdiction” means or what the Supreme Court said in 1898. All of those people are dead. The common-law judges in England with their wigs who invented this rule are even deader. Illegal immigration is a crisis. Shouldn’t we do what makes sense?

Well, I am happy to entertain living-constitution arguments. Some of my best friends are living-constitutionalists! But I wouldn’t choose this case to get behind living-constitutionalism. Imagine telling someone: “You were born here. You went to school here. You’ve never been to China. You don’t know anyone in China. You don’t speak Chinese. The Fourteenth Amendment’s text says that you’re a U.S. citizen. The Supreme Court held in 1898 that you’re a U.S. citizen. But too bad, you’re being deported to China because the Constitution has undergone an epigenetic shift, like the Moirans in Seveneves.” I just don’t think it’s a very attractive argument.

The second is Congress. In 1940, Congress enacted a statute that repeats the words of the Constitution: “a person born in the United States, and subject to the jurisdiction thereof” is a citizen. Since then, everyone has always interpreted the statute to confer birthright citizenship on the children of non-residents and illegal immigrants. Wherefore, it is possible the Supreme Court will say something like: “regardless of whether the Constitution requires birthright citizenship, everyone has assumed since 1940 that an Act of Congress requires birthright citizenship, so we’ll stick with that settled meaning of the statute. We express no view as to whether a statute abrogating birthright citizenship would be constitutional.”

That would be an impressively statesmanlike resolution of the question presented. Everyone would come away happy. The Left would be happy because a Dub is a Dub. The Right would be happy because it opens the door a crack to eliminating birthright citizenship, even though everyone has long assumed the door was shut.

Still, in this iteration of the recurring debate between statesmanship and nerdiness, I am going with nerdiness. It is lame to say that the Constitution, which is worded identically to the statute, might or might not mean something different from the statute. The correct way to resolve the case is to say that the Constitution requires birthright citizenship.

Forward and backward

If you’re trying to figure out the answer to a legal question, you can either reason forward or you can reason backward.

Reasoning forward means applying neutral principles and attempting to deduce the correct legal answer without any preconceived view of what the result should be. You know, balls and strikes.

It is an understatement to say that neutral principles do not always yield an objectively correct answer. There are lots of bitterly divided Supreme Court cases in which every Justice applies, or at least attempts to apply, neutral principles, yet they cannot agree on the outcome. But just because neutral principles aren’t always determinate doesn’t mean they are never determinate. Sometimes, applying neutral principles yields clear answers, even when the subject matter is controversial.

Reasoning backward means starting with the desired result and attempting to reverse-engineer a legal theory supporting that result. It’s what lawyers do for a living: they start with a result (what their clients want) and then figure out how to get there.

Most judges profess to use the balls-and-strikes approach. One notable exception was Richard Posner, who described his method of judging this way:

My approach in judging a case is therefore not to worry initially about doctrine, precedent, and the other conventional materials of legal analysis, but instead to try to figure out the sensible solution to the problem or problems presented by the case. Once having found what I think is the sensible solution I ask whether it’s blocked by an authoritative precedent of the Supreme Court or by some other ukase that judges must obey. If it’s not blocked (usually it’s not—usually it can be got around by hook or by crook), I say fine—let’s go with the commonsense solution.

Few judges are as open about reasoning backward as Judge Posner. But any lawyer will tell you that it sometimes happens behind the scenes.

Judge Posner applies that form of reasoning in a concurring opinion opposing birthright citizenship. He first opines that there’s too much birth tourism, and then says: “We should not be encouraging foreigners to come to the United States solely to enable them to confer U.S. citizenship on their future children. … A constitutional amendment may be required to change the rule whereby birth in this country automatically confers U.S. citizenship, but I doubt it.” In other words, he starts from the premise that birthright citizenship is bad, and then optimistically conjectures that there must be some way to get it done legally.

It’s no coincidence that Judge Posner—one of the few judges to endorse the reasoning-backwards model—is also one of the few judges to have advocated against birthright citizenship. The birthright-citizenship issue is a classic example of an issue for which reasoning forward yields a single correct legal answer, and the sole way to reach the contrary conclusion is to reason backward.

All of the neutral tools of legal interpretation—constitutional text, history, and Supreme Court precedent—point in favor of birthright citizenship. By contrast, the arguments against birthright citizenship are of the following form:

• It would be a good idea to get rid of birthright citizenship.

• If you try hard enough, it is possible to construct a legal theory under which birthright citizenship loses.

Take a look at the government’s briefing in the birthright citizenship litigation. I don’t understand how it’s possible to be persuaded by these arguments unless you have already decided to adopt the anti-birthright-citizenship position and are straining to find a justification for it.

The government’s argument begins unpromisingly (p. 8) with the quotation “jurisdiction … is a word of many, too many meanings,” taken from a case in which none of the possible meanings bears any relationship to the government’s current interpretation. The government then offers the following syllogism (pp. 8-10)

• The argument that “jurisdiction” means “authority” has holes—after all, we do exercise some authority over diplomats, and Congress has broad authority to regulate Indian affairs.

• Therefore, we’re going to say that “jurisdiction” means “allegiance.”

• And mirabile dictu, we will declare that Wong Kim Ark had “allegiance” from the moment he was born but the children of non-residents and illegal immigrants don’t have “allegiance.”

Look … I just don’t see how you can say that the government’s position represents the best meaning of “jurisdiction.” The jurisdiction-equals-authority theory neatly fits all data points. By contrast, the notion that Wong Kim Ark had some greater degree of “allegiance” than children of other non-citizens is completely made up. What the government is really saying here is: “because the jurisdiction-equals-authority theory isn’t perfect, the door is ajar to depart from the birthright-citizenship position.” Well, maybe; but a judge wouldn’t open that door and walk through it unless the judge was searching for a reason to abolish birthright citizenship.

The government next says (p. 10) that the Fourteenth Amendment must be read the same way as the Civil Rights Act of 1866, which provided: “all persons born in the United States and not subject to any foreign power, excluding Indians not taxed, are hereby declared to be citizens of the United States.” I fail to understand how this theory helps the government distinguish Wong Kim Ark. Wong Kim Ark’s parents were Chinese citizens, and hence “subject to” a “foreign power.” If Wong Kim Ark himself was nonetheless not “subject to any foreign power,” why would the analysis be any different for the children of non-residents and illegal immigrants?

More fundamentally, why would we assume that the Fourteenth Amendment means the same thing as the Civil Rights Act? They’re worded differently. At the debates over the Fourteenth Amendment, the debaters realized that the wording was different. For instance, Senator Trumbull opined: “I think this language is better than the language employed by the civil rights bill.” If we’re trying to get to the best legal answer, why not interpret the text of the Constitution rather than statutory language that the drafters of the Fourteenth Amendment made a conscious decision not to use?

Next, the government observes (p. 11) that the Fourteenth Amendment uses the phrase: “citizens of the United States and of the States wherein they reside.” The government then cites some random Illinois state court case from 1840, which hasn’t been cited in the last 98 years, stating that an “inhabitant … has a fixed and legal settlement.” Based on this, the government heroically concludes that the word “reside” excludes illegal immigrants (and apparently also the children of illegal immigrants?), so they don’t “reside” in a state, so they can’t be “citizens of the United States.” When you contrast this extremely convoluted theory with the straightforward arguments for birthright citizenship, there’s no way you could actually be persuaded the theory is correct unless you define “correct” as “whatever will get me to the desired result of eliminating birthright citizenship.”

The government makes other arguments, but I don’t think it’s a productive use of space to rebut every single one of them. You will have to trust me that they are all weak. If you think one of them is strong, leave a comment and I’ll gladly address it.

It’s not just the government’s brief. Take the recent New York Times guest essay by Professors Barnett and Wurman on this issue. It is entitled “Trump Might Have a Case on Birthright Citizenship,” which to me doesn’t express much confidence in the legal argument to follow. It opens by emphasizing that Wong Kim Ark doesn’t “squarely” resolve the issue, which again seems inauspicious. After that, it leads off the anti-birthright-citizenship argument by quoting an 1862 opinion by Edward Bates, Abraham Lincoln’s Attorney General, addressing the citizenship status of free Black Americans. It then turns to a statement from Blackstone on the general topic of “allegiance” before turning to other, even less relevant sources.

I find the 1862 document hard to follow. You are free to read the back-and-forth-and-back on the Internet about exactly what Edward Bates was trying to say in 1862. However, we should not overlook the forest for the trees. The pro-birthright-citizenship argument has on its side the constitutional text, centuries of history, numerous explicit statements in a seminal Supreme Court case, and 127 additional years of history following said seminal case. The anti-birthright-citizenship argument, at least according to the essay, leads off with: (1) Wong Kim Ark doesn’t “squarely” resolve the question, and (2) if you squint, you can find some support for the anti-birthright-citizenship position in extraneous statements in a document that addresses a separate topic and was written at a time that the Fourteenth Amendment didn’t exist. Exactly like the government’s brief, it’s saying: “if you really want birthright citizenship not to exist, then you can, through Herculean efforts, construct some theoretical legal argument in favor of the anti-birthright-citizenship position!”

The horseshoe

What type of judicial philosophy would produce a ruling against birthright citizenship?

Well, any judge who would author such an opinion would likely have a conservative reputation. But from a methodological perspective, such a judge would fit in well in the Yale Law School faculty lounge.

I’ve opined before about the horseshoe theory of law: the tendency of the methodologies of very progressive and very conservative judges to converge. Judges at both ends of the ideological spectrum tend to view judging as a species of cause lawyering. They may differ on which causes are righteous, but their view of the judge’s role is the same—to vindicate a cause if an argument is theoretically available to support it.

This view of judging is traditionally associated with the legal Left. One can find many law review articles endorsing the view that judges are charged with doing Justice, with Justice defined in progressive terms. But experience has taught that some judges on the legal Right view judging the same way.

The anti-birthright-citizenship position is a quintessential example of a position that prevails only in front of a judge on the right end of the horseshoe. It requires the conjunction of conservative policy views and a willingness to disregard neutral principles in order to reach results consistent with those views.¹

I don’t have strong views about whether birthright citizenship, as a policy matter, is good or bad. But I do have strong views that neutral principles exist and judges should try their best to use them. I’m also idealistic enough to believe that most judges agree. We’ll see.

1. The alert reader will note that Judge Posner himself was not exactly a “conservative.” Judge Posner is unique. He’s the exception that proves the rule.