In his presidential campaign, Donald Trump has doubled down on bashing migrants crossing the southern border. They are criminals who are “poisoning the blood of our country,” he says. The Republican National Convention was full of talk of surging “migrant crime,” even though such a rise does not exist.

The number of Americans who think the immigration level is too high has sharply risen since the last presidential contest in 2020, and as Americans move to the right on the issue, Trump plans to go much further than President Biden’s executive order in June, which closes the border when crossings surge. Trump has said he would build “vast holding facilities” — detention camps — to lock people up as their cases progress; end birthright citizenship, even though the Constitution protects it; and bring back a version of the travel ban from his first term, which barred visitors from several mostly Muslim countries. Another Trump promise, mass deportations, hasn’t been tried since the 1950s; now, polls show majority support for it, including among Latinos.

But there is one anti-immigration proposal on the right that Trump doesn’t talk about publicly. It’s a spin on “self-deportation.” The term — for provoking immigrants to leave of their own volition — has gone out of fashion but the idea continues to lurk. This time, instead of directly pressuring undocumented adults to flee, some immigration opponents are threatening access to school for their children. It’s a nuclear option — requiring the reversal of a Supreme Court ruling that has been a linchpin of educational rights for four decades — that some of Trump’s allies on the right are quietly building support for.

In February, the Heritage Foundation, a right-wing Washington think tank that’s become central to mapping out policy objectives for the next Republican administration, recommended requiring public schools to collect data on immigration status when students enroll. Heritage also said schools should charge tuition for children who are undocumented or who have a parent who lacks legal status.

About 600,000 undocumented children live in the country, and another 4.5 million have a parent who is here illegally. To ensure that parents can send their children to school without fear of immigration agents, the Biden administration declared in 2021 that U.S. Immigration and Customs Enforcement could take no actions of any kind at schools and other locations where young people gather, like universities and day care centers. It’s easy to see why schools are such a sensitive site of immigration enforcement. Barring children from the classroom punishes them for their parents’ decisions and disrupts families’ daily rhythm. Most searingly, perhaps, it undermines the hope of bettering the lives of the next generation — a reason for coming to the United States in the first place.

It has always been difficult to deter people from migrating to the United States, given instability in their home countries and the lure of economic opportunity at American businesses that depend on cheap labor. But there is a grim logic to the strategy of keeping children out of school in the United States — that if you go so far as to take away a right fundamental to the American dream, people will leave.