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“It is proper to take alarm at the first experiment on our liberties,” James Madison wrote in 1785. President Donald Trump confirmed Tuesday that he plans to move from experimentation on liberty into widespread application of the tyrant’s playbook.  

In an interview with Axios on HBO, Trump confirmed what had been suspected since last summer: He is planning an executive order that would try to change the meaning of the Constitution as it has been applied for the past 150 years—and declare open season on millions of native-born Americans.

The order would apparently instruct federal agencies to refuse to recognize the citizenship of children born in the United States if their parents are not citizens. The Axios report was unclear on whether the order would target only American-born children of undocumented immigrants, children of foreigners visiting the U.S. on nonpermanent visas—or the children of any noncitizen.

No matter which of these options Trump pursues, the news is very somber. A nation that can rid itself of groups it dislikes has journeyed far down the road to authoritarian rule.

The idea behind the attack on birthright citizenship is often obscured by a wall of dubious originalist rhetoric and legalese. At its base, the claim is that children born in the U.S. are not citizens if they are born to noncitizen parents. The idea contradicts the Fourteenth Amendment’s citizenship clause, it flies in the face of more than a century of practice, and it would create a shadow population of American-born people who have no state, no legal protection, and no real rights that the government is bound to respect.

It would set the stage for an internal witch hunt worse than almost anything since the anti-immigrant rage of the 1920s.

Birthright citizenship is a term that many Americans had not heard until recently. But it is a key to the egalitarian, democratic Constitution that emerged from the slaughter of the Civil War. In 1857, the pro-slavery majority of the Supreme Court held that citizenship was racial; in Dred Scott v. Sandford, Chief Justice Roger B. Taney wrote that people of African descent were not American citizens—and never could become citizens, even through an act of Congress. At the time the Constitution was written, he wrote, black people were “regarded [by whites] as beings of an inferior order, and altogether unfit to associate with the white race, either in social or political relations; and so far inferior, that they had no rights which the white man was bound to respect.”

The decision spurred a wave of revulsion throughout the free states and probably hastened the start of the Civil War. In fact, almost since the founding of the republic in 1789, opponents of slavery insisted that American citizenship had always been the birthright of all people born in the United States. After Appomattox, the 39th Congress met with the urgent purpose of undoing the constitutional damage wrought by Taney and what they called the “Slave Power.” The result was the Fourteenth Amendment. Here is the wording of Section 1:

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. No State shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States; nor shall any State deprive any person of life, liberty, or property, without due process of law; nor deny to any person within its jurisdiction the equal protection of the laws.

This is a fairly intricate piece of legal machinery, set in place after months of deliberation by some very acute legal minds. Its centerpiece is the idea that citizenship in the United States is universal—that we are one nation, with one class of citizens, and that citizenship extends to everyone born here. Citizens have rights that neither the federal government nor any state can revoke at will; even undocumented immigrants—“persons,” in the language of the amendment—have rights to due process and equal protection of the law.

The citizenship-denial lobby has focused on the words subject to the jurisdiction. Its members argue that citizens of foreign countries, even if they live in the U.S., are not subject to U.S. jurisdiction, and thus their children are not covered by the clause. To test this idea, ask yourself: If a foreign citizen rear-ends your car on your drive home today, will you, or the police, allow him to drive away on the grounds that a foreign citizen cannot be arrested, ticketed, or sued?

For those scoring at home, the answer is no.

Foreign citizens are “subject to the jurisdiction” of our police and courts when they are in the U.S., whether as tourists, legal residents, or undocumented immigrants. Only one group is not “subject to the jurisdiction”—accredited foreign diplomats and their families, who can be expelled by the federal government but not arrested or tried.

That’s who the framers of the clause were discussing in Section 1—along with one other group. In 1866, when the amendment was framed, Indians living under tribal rule were not U.S. citizens. Under the law as it was then, American police could not arrest them, and American citizens could not sue them. Relations with Indian tribes were handled government to government, like relations with foreign nations: If Native people left the reservation and harmed American citizens, those citizens had to apply to the U.S. government, which would officially protest and seek compensation from the tribal government. In that respect, Indians living under tribal government were as protected as foreign diplomats are today.

But over and over in the Fourteenth Amendment debates, the framers of the amendment made clear that there would be no other exclusions from the clause. Children of immigrants? They were citizens. Even children of Chinese immigrants, who themselves weren’t eligible to naturalize? Yes, them too. Mysterious foreign “Gypsies,” who supposedly spoke an unknown language and worshipped strange gods and observed no American laws? Yes, the sponsors explained, it covered them too.

The framers of the clause understood about immigration. The issue had been a divisive one throughout the 1850s, spawning the Know-Nothing movement and state attempts to bar immigrants from citizenship. The percentage of foreign-born residents of the U.S. in 1866 was just over 13 percent—roughly what it is today.

And in the ranks of the Union Army that saved the nation, roughly 20 percent of soldiers were foreign-born.

Three decades later, the government tried to meddle with the clause by denying citizenship to Wong Kim Ark, the child of Chinese immigrants who were themselves not eligible for citizenship. The Supreme Court reaffirmed that the clause meant what it said. No matter where their parents were born, no matter what their parents’ status, American-born children are Americans. And that’s how it should be.

The assault on birthright citizenship is an onslaught on civic equality for all of us. Nativists have grown more strident over the past decade or so. First, they advocated for a constitutional amendment to strip citizenship from the children of aliens; then they argued that citizenship could be stripped by statute; now, in the Trump era, they claim that it can be done with the stroke of a pen. It is an idea that has crawled slowly from the fever swamps of the far right into the center of our discourse, growing more outlandish with each step.

The executive-order idea was floated as a trial balloon in July in an op-ed piece in The Washington Post by former White House official Michael Anton. Anton’s sole book is The Suit: A Machiavellian Approach to Men’s Style, which details a Florentine Renaissance approach to menswear on the job. In the Post piece, Anton inaccurately reproduced a quote from Senator Jacob Howard, the sponsor of the Fourteenth Amendment, in a manner that made Howard seem to support Anton’s position (the Post, under enormous criticism, eventually acknowledged the alteration). And in fact, every bit of the scant scholarship Anton relies on in that piece is as phony as a Confederate $100 bill. (I once debated the scholar who was the source of most of it, and pointed out that almost all his evidence was not just erroneous, but faked.)

That is one of the two takeaways from today’s news: Trump, Anton, and their enablers are relying on phony history and altered documents in an attempt to change the American constitutional order. (The facts are readily available; for my own contributions, see here, here, here, here, and here.) Those who don’t want to take my word for it can consult this essay by James C. Ho, a conservative “originalist” who was recently appointed to the U.S. Court of Appeals for the Fifth Circuit by Donald Trump. Ho and I agree on little except this: The citizenship clause means what it says.

If the administration attempts to strip citizenship from millions of Americans—millions of people who have never known any other country—the trapdoor to dictatorship will have fallen open. The executive order cannot be enforced without a huge apparatus of internal control. Immigration and Customs Enforcement will, of necessity, become the skeleton of a nationwide citizenship police. Each of us must be prepared to prove our membership in the nation at any moment. And the new population of stateless Americans will face persecution, detention, and abuse; Korematsu-style internment camps would be a logical next step.

Our Constitution is a gift to us from the generations that went before, and particularly the millions who died in the Civil War; the Fourteenth Amendment is the centerpiece of that Constitution. If we let Donald Trump destroy it, then history will regard both him and us with equal contempt.

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