A droll Politico headline earlier this week nicely summed up the state of bemusement and incomprehension surrounding the Republican Party’s revived fixation with ending birthright citizenship.

“Trump to O’Reilly: 14th Amendment is unconstitutional.”

Fox News' Bill O’Reilly grilled Trump on Tuesday, based on the widely shared premise that ending birthright citizenship would require changing the Constitution to excise or edit the first sentence of the Fourteenth Amendment. That sentence states, “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.”

Republicans are racing to catch up with Trump, creating a fresh consensus among the party's presidential candidates that birthright citizenship is bad, and a presumption among most critics and reporters that these candidates believe the Constitution is flawed, and should perhaps be changed.

Neither of these presumptions necessarily describes anti-birthright candidates. Many Republican presidential hopefuls share the belief that giving the children of immigrants citizenship automatically is bad. In less abstract terms, they’re affirming an unfounded nativist anxiety that birthright citizenship creates an incentive for child-bearing immigrants to stream across the border and secure all the benefits of citizenship, including welfare, for their offspring—what conservatives derisively refer to as “anchor babies." But they disagree among themselves over how to address the problem. And because the point of contention is so politically toxic—a dramatic shift to the right relative to the also-toxic Republican primary consensus in 2012—the candidates have little interest in explaining their personal theories of how the imaginary "anchor baby" crisis should be resolved.

All of the possibilities are equally crazy.

Under the status quo, the children of undocumented immigrants are conferred citizenship by the Fourteenth Amendment. If you believe this is bad, and that we should be willing to tolerate a permanent, minority underclass of stateless noncitizens, you can address it in three ways: by changing the Constitution, by stepping up enforcement so dramatically so that all unauthorized immigrants are expelled before they give birth, or by getting courts to reinterpret the Constitution as it is currently written.

In general, the Republicans who want to change the subject from birthright citizenship to literally anything else pay lip service to the issue. But they insist, for better or worse, that citizenship is a constitutional right of the children of immigrants, and that the Constitution is not going to change. Marco Rubio and Jeb Bush are in this category. Both intimate that they oppose automatic citizenship for the children of people without any documentation who are trying to game the Fourteenth Amendment, but argue that the right is enshrined, and it isn’t going away.

Perhaps intentionally, they are blinding themselves to the other strategies. In a statement to reporters earlier this week, Scott Walker’s spokeswoman explained how he would tackle the issue. "We have to enforce the laws, keep people from coming here illegally, enforce e-verify to stop the jobs magnet and by addressing the root problems we will end the birthright citizenship problem." If there were no undocumented immigrants in the country, then birthright citizenship would become a mere abstraction. Without touching the Constitution, Walker suggests he would use a draconian enforcement regime to effectively moot the birthright clause of the Fourteenth Amendment. This is almost certainly not feasible, but it lays down a marker for immigration enforcement on the rightmost conceptual end of the policy debate—promising to deport immigrants at such an intense clip that vanishingly few will remain in the country long enough to give birth.

Trump’s goal is even more ambitious. He supports a Walker-like anti-immigrant police-state, too, but argues that the Fourteenth Amendment doesn’t say what it appears to say. A popular argument on the fringes of conservative legal thought holds that the original meaning of the Fourteenth Amendment—and of the term “jurisdiction” in particular—precludes the notion that it should create a right to citizenship for the children of non-citizen immigrants. Trump has bought into it. He’s not a fan of amending the Constitution, as he told O’Reilly, because “It’s a long process, and I think it would take too long. I’d much rather find out whether or not anchor babies are citizens because a lot of people don’t think they are.” This flies in the face of a century and a half of law. It was the source of O’Reilly’s confusion, and of the tongue-in-cheek Politico headline. To test the theory, a conservative state government could pass a law stripping citizenship benefits from children of immigrants, and defend it in court. This would be easy to laugh off in a different milieu, but in a world where scores of federal judges and three or four conservative Supreme Court justices are willing to vouchsafe plainly absurd and self-serving conservative legal arguments, it is alarming. Especially if you consider the possibility that a Republican candidate wins the presidency on an anti-birthright platform, and obtains the power to nominate nativists to the federal bench.

These views are so extreme that they're often dismissed as harmless campaign trail pandering. Since the Constitution isn’t going to be amended anytime soon, at least not for this purpose, most reporters don't take the anti-birthright frenzy as much more than a garden variety Republican primary spectacle. That’s a big error. GOP candidates are telling us how they would use levers at their disposal to antagonize immigrants, and we should be listening.