Last month, I predicted that declining migration and enhanced border security were subtly transforming the political logic of immigration reform. This prediction is still likely to hold true, but admittedly, it did not factor in the GOP primary—especially the impact of Donald Trump. Trump has almost zero chance of landing the GOP nomination, but that has not stopped him from setting the terms of its policy debate. Now, in calling for the repeal of birthright citizenship, Trump may even be pulling rivals in his direction: Scott Walker seems to be moving towards Trump’s view; Bobby Jindal tweeted his agreement; and other longtime skeptics in the race, like Lindsey Graham, are reminding reporters that they got there first.

It’s important not to overstate the novelty of this latest crusade against birthright citizenship. It’s not without (somewhat recent) precedent: In 1996, the GOP platform, adopted in San Diego, declared: “We support a constitutional amendment or constitutionally valid legislation declaring that children born in the United States of parents who are not legally present in the United States or who are not long-term residents are not automatically citizens.” The language was drafted amidst an immigration panic that dwarfs anything seen during this Administration, but even at the time, the language was so dicey that Bob Dole disavowed it during the campaign. Today, with the undocumented population stable after years of growth, with migration from Mexico to the United States in sharp decline, and with stepped-up deportations and border security, the hysteria seems even more out of place. Events have rendered dubious the idea that birthright citizenship is, as Trump puts it, “the biggest magnet for illegal immigration,” and is in need of immediate scrapping.

Besides, why shouldn’t Americans celebrate the idea of birthright citizenship? It’s probably the most powerful affirmation of our civic nationhood—a guarantee that American citizenship is given to anybody born here, regardless of their lineage or descent. Granting citizenship by the accident of birth is a sign of our public indifference to the political significance of bloodlines—an ideal that remains valuable, even if our practice frequently falls short of it. There are other ways to confer citizenship, of course, and some thinkers—sensitive to the reality that many desperate people are simply too far away to guarantee a better life for their children by crossing a border—have noted that, in some ways, birth in a wealthy country like the United States can confer privileges disturbingly similar to fortunate family ties. Others note that active democratic citizenship should require something more demanding than the simple accident of birth. (This latter objection implicates all of us, not just the children of undocumented immigrants.)

These are fair objections, and well-intentioned ones. In other words, they’re not the ugly, pandering complaints that Republican candidates are making. How far the party has come: not a path to citizenship, or even a path to legal status, but a change in the Constitution to say that even your children—born on this land—bear the stain of their parents, a stain so indelible that they cannot count as members of our democracy, and may have to be kicked out to a “home” country they’ve never seen. This is ugly nativism presenting itself as civics. Luckily the Republicans of the nineteenth century cemented their vision in the Constitution—protecting one of their finest achievements from the Republicans of the twenty-first.