One hundred years and nine days after the Johnson-Reed Act of 1924 took effect—banning immigration into the United States from any place except northwest Europe—President Biden issued an executive order today that will reduce the flow of asylum seekers across our southern border. That he did so reluctantly is a matter of record, as he had condemned then-President Donald Trump for taking a similar action in 2018. But do it he did, responding to polling that shows his handling of the southern border is one of his two greatest electoral vulnerabilities (high prices are the other) as he endeavors again to keep Donald Trump out of the White House.

The substance of the order comes as no surprise, as the numbers involved are comparable to those in a Biden-backed bill that congressional Republicans, under pressure from Trump, rejected earlier this year. It enables Biden to close the border when the previous week’s number of unauthorized border-crossers, the vast majority asylum seekers, exceeds a daily average of 2,500. (Unaccompanied minors will be let in regardless.) Unlike Biden’s doomed legislation, the order does not contain provisions to increase the number of immigration judges and border guards to deal with the flow: Only Congress can authorize such measures. And only Congress can authorize immigration reforms that have been widely popular for the past two decades, like the provisions in the DREAM Act that would give legal standing to undocumented immigrants who were brought into the country when they were children. The DREAM Act has been languishing in Congress for close to 20 years.

As the White House knew it would, Biden’s action drives a wedge into Democratic ranks, much as his response to Israel’s war on Gaza already has. The divisions over his order, however, don’t conform neatly to left vs. center. Progressive mayors like Chicago’s Brandon Johnson have asked the administration for help in dealing with the unheralded arrival of thousands of immigrants into their cities. Swing-district House members have made clear that their prospects, and Biden’s, would brighten if he found a way to reduce the number of unauthorized border crossings. Progressive Arizona Rep. Ruben Gallego, now the Democratic candidate for the Senate in his very swingish state, backed Biden’s action.

And, of course, the demonization of immigrants has become such a constant of right-wing media that many of its largely working-class consumers view Biden as unwilling to defend the America that presumably would exist if immigration altogether ceased. Those who want it simply stopped will be voting for Trump, but Biden and the Democrats plainly hope that by setting numerical limits, he can win a share—doesn’t have to be large—of the voters who have viewed the border as "out of control" but also don’t want Trump in the White House.

Will today’s order survive judicial review? Trump’s analogous order failed to pass muster with the courts; he was only able to close the border in 2020, via emergency pandemic rules. Had the legislation earlier this year passed Congress, the courts might well find it constitutional, but as it failed, Biden’s order may be on shaky ground. Ironically, it’s the Republican-appointed justices on the Supreme Court who may be most inclined to accept it, even as their Democratic-appointed counterparts are more likely inclined to strike it down.

After all, Biden’s order runs counter to what’s been mainstream Democratic policy since 1965, when Lyndon Johnson and the Great Society Congress repealed the Johnson-Reed Act and effectively opened our borders. Since he became a senator in 1973, Biden has supported that policy, as well as the immigration reforms that consistently failed to overcome Republican opposition. But the upcoming election and the polls, like a hanging, have concentrated the mind (both his and much of his party’s) despite what I suspect are the wishes of the heart.