Typically confined to a White House where his circle of close allies is slowly shrinking, Donald Trump reportedly took advantage of his weekend trip to Mar-a-Lago to meet with some of his more opinionated friends, many of whom are employed by Fox News. Shortly after this meeting, the president unleashed a tirade of anti-immigration tweets, including, “Border Patrol Agents are not allowed to properly do their job at the Border because of ridiculous liberal (Democrat) laws like Catch & Release. Getting more dangerous. ‘Caravans’ coming,” and, later, “These big flows of people are all trying to take advantage of DACA. They want in on the act!” He kept at it on Monday, referring to “caravans” of immigrants crossing the border just minutes after the topic came up on Fox & Friends.

Trump’s tantrum, of course, was completely in character, but it was based on a glaring factual error: people who arrived in the United States after 2012 are not eligible for DACA protections. And though much of what Trump says can (and does) go ignored in Washington, where most have realized that they’re better off overlooking his half-baked policy whims, in this case his utter ignorance may have a significant impact. He torpedoed a deal to offer protections to DACA recipients back in January, welching on on his spoken agreement with Senate Minority Leader Chuck Schumer. And though Trump attempted to patch up that misstep last month, neither Republicans nor Democrats bit.

Trump’s passions on immigration have been piqued since he signed a budget bill late last month that included zero border-wall funding, sending a shock wave of fury through his voting base that an eleventh-hour veto threat did nothing to mitigate. Now, observers say his renewed focus on immigration smacks of a campaign to obtain funding by other means. “He’ll say anything he can say at the moment that he thinks will get him his wall,” Democratic congressman Steve Cohen told MSNBC. “Last week he said Democrats didn’t want to help the kids. ‘He loves the Dreamers and wants to have DACA, but the Democrats are stopping him. He’s doing all he can.’ It’s all about the wall, and the wall is all about him.” (Faced with a budgetary dead-end, Trump recently proposed that the U.S. military ought to pony up the cash for the wall.)

If anything, though, Trump’s stubborn unwillingness to learn any sort of policy detail has baffled everyone—Democrat and Republican—who has attempted to negotiate with him, much less conceptualize serious immigration reform that goes beyond construction of a border wall. In 2017, he appeared open to negotiating with the Democrats over a deal, to the point that he threw his Republican allies under the bus to side with “Chuck and Nancy” during a budget showdown. In the intervening months, however, he flipped back and forth, demanding either an end to chain migration, or a border-wall fund, in exchange for a possible a path to citizenship. And at the heart of each flip, as my colleague T.A. Frank explained, his his fundamental ignorance: