If Trump is the least bit serious about changing immigration law, however, rather than just demagoguing about it, he will have to radically change his approach—and himself. Right now, it is practically impossible for him to overcome the complete lack of trust on Capitol Hill, given his seeming inability to keep his word or hold a consistent position for more than five minutes—a frustration shared by both sides of the aisle but felt acutely by Republicans. If he cannot fix those relationships in Congress, they could haunt his presidency. The conservative base is prone to revolt over compromise immigration legislation, and that’s before Trump takes to Twitter to finger Republicans for going wobbly on his aggressive agenda.

With the proper assurances, Trump could soothe his base, bring Fox News in line, and give conservative lawmakers cover to pass a bill. But congressional Republicans have no faith that Trump won’t betray them if they stick their necks out for him. Who’s to say they won’t deliver him a bill that protects the Dreamers—one of Trump’s four pillars—only to have the president complain afterward that he never really wanted to sign a bill with an “amnesty” provision but was forced into it by those wimpy Republicans in Congress? Last year, House Republicans managed to agree on legislation to partially dismantle the Affordable Care Act, bridging the divide between caucus moderates and conservatives in no small part because Trump demanded their vote. He proceeded to refer to the package as a “mean bill,” casting anyone who aided his agenda as heartless.

Republican strategists fear that the same political dynamic could doom immigration reform. The conservative base is loyal to Trump and in a constant state of simmering revolt. The party leadership is ready to act, but is wary of taking a political risk at a time when Republican moderates are fast becoming an endangered species.