On Friday, CNN and NBC News reported that President Donald Trump may end DACA, an Obama-era program that allows undocumented immigrants brought to the United States as children to live and work here lawfully. CNN, for its part, said Trump is “considering” such a move, while NBC described it as “likely.” The possibility that the president will deport up to 800,000 young people, most of them Latino, was widely interpreted by progressives as an extension of the administration’s white nationalist ideology. It’s important to note, though, that phasing out DACA wasn’t Trump’s idea. Rather, the bulk of the blame for killing DACA will fall on the Republican Party.

President Barack Obama introduced DACA, or Deferred Action for Childhood Arrivals, in 2012 after Congress failed to pass the DREAM (Development, Relief, and Education for Alien Minors) Act. DACA-eligible individuals receive a two-year renewable deportation deferral and are permitted to live and work in the United States. The policy reflected Obama’s interpretation of current federal law, which directs the executive branch to establish “national immigration enforcement policies and priorities”—a reasonable grant of power since the government cannot deport everyone at once. With DACA, Obama simply deprioritized the deportation of one group of immigrants.

Republicans criticized DACA as executive overreach and successfully sued to block Obama from expanding the program to the undocumented parents of lawful residents. The 2016 Republican Party platform slammed DACA as “unlawful amnest[y],” and Trump promised to end it. But his Department of Homeland Security has continued to issue and renew DACA permits even as its law enforcement wing occasionally targets DACA recipients for deportation. In June, DHS announced that DACA would remain in effect for the time being.

Shortly thereafter, a coalition of Republicans sent Attorney General Jeff Sessions an ultimatum: Kill DACA by Sept. 5 or we’ll take you to court. The letter argued that DACA is illegal and that the signatories were prepared to sue the Trump administration for allowing its continuation. Idaho Republican Gov. Butch Otter signed the letter, as did the GOP attorneys general of Alabama, Arkansas, Kansas, Louisiana, Nebraska, Idaho, South Carolina, Tennessee, Texas, and West Virginia. Texas Attorney General Ken Paxton spearheaded the effort.

This threat put the administration in a tricky position. Until then, it had been able to maintain DACA as a kind of institutional compromise: a policy that it wouldn’t have implemented but wasn’t eager to jettison. Paxton’s letter forced the administration to take a stand. If it didn’t kill DACA, it would have to devote time, resources, and political capital to defending it in court. Republican voters would presumably not be happy to learn that Trump was sticking up for a policy that the party platform lambasted as unlawful.

According to NBC News, this letter has played a significant role in the White House debate regarding DACA’s fate in that it “sparked discussions inside the Trump administration over whether it would be willing to defend the program in court.” These discussions seem to have ended with the decision to kill, or at least “phase out,” DACA. The president who rode to office on a wave of xenophobia, it seems, was not prepared to mount an argument on behalf of undocumented immigrants.

If and when Trump formally ends DACA, he will be rightly criticized for depriving nearly 800,000 people of their liberty and livelihood. The move will be particularly egregious in light of his overt sympathy for violent white supremacists like Charlottesville’s neo-Nazis and Joe Arpaio. It will be interpreted, correctly, as an attack on the Hispanic community—a further effort to drive Latinos into hiding and out of the country. In many ways, it is a distillation of Trumpism.

But it was the pre-Trump Republican Party that sank the DREAM Act and assailed DACA from the start, and it is Republicans outside the administration who seem poised to force Trump to kill it. Hostility toward dreamers—young undocumented immigrants who may have known no other home but America—is mainstream in the modern GOP. If it weren’t, Republicans would’ve helped pass the DREAM Act long ago. Trump will take a lot flack for ending DACA, and he’ll deserve it. But the truth is that Republican politicians forced his hand. Republican xenophobia predates Trump, and it’ll outlive him, too.