On Wednesday, Sarah Huckabee Sanders, Donald Trump’s dogged press secretary who is eternally stuck on cleanup duty, was forced to tread even more carefully than usual. Earlier that day, her boss retweeted a series of videos from a far-right British activist depicting unverified incidences of violent Muslim behavior. The veracity of the videos could not be proven—and in fact, had previously been called into question by the British government—but much like his past proclamations about the “alt-left”, losing the popular vote, and Barack Obama’s birth certificate, it didn’t stop Trump from electing to feature them on his Twitter feed. When asked by reporters why Trump had promoted them, Sanders essentially shrugged. “Whether it’s a real video, the threat is real,” she said. “His goal is to promote strong border security and strong national security.”

Trump is no stranger to publicly undermining his own agenda—his calls for the New York truck terrorist to receive the death penalty, for example, made it harder for the government to assure an impartial trial. But his choice to feature the videos could potentially have the most far-reaching impact yet, undercutting the White House’s efforts to deepen ties with Saudi Arabia, a Muslim-majority country, in order to cajole the nation into cooperating on Iran; torpedoing Secretary of State Rex Tillerson’s efforts to resolve a dispute between Qatar and other U.S. Gulf allies; and having a potentially disastrous impact on Jared Kushner’s efforts to chart a new peace plan between Israel and Palestine—an effort that’s already on the rocks after the White House threatened to close a Palestinian mission in Washington. But like his previous comments, the tweeter in chief’s actions on Wednesday could also derail one of his pet projects: the travel ban.

That Trump still harbors deep suspicions against Muslims is no surprise, considering the years he spent condemning them, railing against “radical Islamic terror,” and campaigning on the promise of enacting a travel ban against Muslim-majority countries. But once he reached office, those promises and pronouncements caught up with him. The first travel ban he enacted shortly after assuming the presidency died a messy death in the Ninth Circuit largely thanks to comments made by the president himself; in its June ruling, the court highlighted a tweet Trump sent during the campaign saying that he wanted to implement a “TRAVEL BAN for certain DANGEROUS COUNTRIES.” An October ruling in Maryland also cited Trump’s tweets, dismissing the argument that the latest iteration of the travel ban “was arrived at through the routine operations of the government bureaucracy,” and noting that “the public was witness to a different genealogy” in the form of a September tweet by Trump.

But the Trump administration has refused to let the ban die a peaceful death, implementing a third version, which activists are again seeking to challenge in court. And Trump’s newest retweets could unwittingly hand them a weapon. “Some of the complaints about the judicial opinions, with respect to the first and second ban, relied on pre-inauguration statements that the president made before he took office,” U.C. Irvine law professor Leah Litman told me. “These more recent statements are now almost a full year into office, so they can’t be discarded for that reason.” She added that, regardless of how much effort and research the government puts into devising a rationale for the latest iteration of the ban, Trump has just proven that he still has a religious animus in mind. Even if that wasn’t his intended message, the public’s understanding of the bill—particularly its anti-Muslim implications—would weigh into the court’s eventual decision, a precedent prominently used in striking down the “separate but equal” laws dotting the South during Jim Crow. “Everyone understood it as a symbol of inequality and supremacy,” she pointed out. “That kind of analysis does affect the court’s reasoning.”