Donald Trump’s domestic agenda suffered another setback Monday night as two Republican senators announced that they would oppose the Senate Republican bill to repeal and replace Obamacare, administering a calamitous blow to the president’s top legislative priority, and making it impossible for the bill to pass in its existing form. Both defections—Jerry Moran of Kansas and Mike Lee of Utah—came from the conservative camp, which has criticized the Senate bill for not doing enough to dismantle the Affordable Care Act. Two other Republican senators, Rand Paul of Kentucky and Susan Collins of Maine, had already publicly declined to support the bill, depriving Senate Majority Leader Mitch McConnell of the votes he needed to proceed. “Regretfully, it is now apparent that the effort to repeal and immediately replace the failure of Obamacare will not be successful,” he said in a statement late Monday night.

Trump, already in danger of looking like a lame duck as the expanding Russia scandal consumes his presidency, was blindsided by the collapse of the G.O.P. bill. Apparently unaware that the Better Care Reconciliation Act was on the verge of defeat, the president had spent his afternoon posing with fire engines and other big trucks that were parked on the White House lawn for “Made in America Week.” Later Monday night, just as Moran and Lee were preparing their statements, Trump hosted a health-care strategy session over steak and succotash, Politico reports, during which he warned the assembled senators about the political ramifications of failing on their promise to replace Obamacare. “He basically said, if we don’t do this, we’re in trouble,” said one person briefed on the meeting.

Trump didn’t invite Moran, Lee, or any number of other ambivalent senators to attend the dinner—the latest in a long series of political missteps that have defined the president’s erratic approach to health care. Repealing and replacing Obamacare, an increasingly popular law under which some 20 million people have gained health-care coverage, was always going to be a hard lift. Conservatives and centrists have clashed repeatedly over how to reform insurance markets, with the far right pushing for the eradication of subsidies, social programs, and regulations designed to protect poor, sick, and elderly Americans, and moderate Republicans expressing concerns about hurting their most vulnerable constituents. Through it all, Trump has oscillated wildly in his approach: suggesting the government should pay for anyone who can’t afford care, then calling on the current system to implode; cajoling House Republicans into passing their own version of Obamacare repeal, and then calling the bill “mean” and “cold-hearted”; blaming Democrats for Obamacare’s weaknesses and then advocating repealing the law with no replacement in order to force their hand. The only thing that has remained consistent is that Trump has remained steadfastly focused on securing a win—any kind of win, regardless of the policy details.

Of course, the devil has always been in the details. After McConnell’s first efforts to rewrite the House bill failed to muster sufficient enthusiasm, he produced another version that veered to the right in certain areas, while attempting to keep moderates happy, too. That the latest round of objection comes from the conservative faction of the party is another factor that will not reflect well on the persuasive powers of the current administration. Left with a still-stagnant bill, which is fast becoming seen as a toxic symbol of the White House's inability to execute its agenda, the G.O.P. are left with few options besides taking up Trump’s suggestion, delivered via Twitter Monday night, to “just REPEAL failing ObamaCare now & work on a new Healthcare Plan that will start from a clean slate.”

McConnell, it seems, will take the president’s advice, if only to be done with the vote once and for all. In his statement Monday night, the Senate majority leader outlined plans to vote now on a measure to repeal the Affordable Care Act, fixed with a delay mechanism that would provide a “stable transition period” for some new, as-yet-undefined legislation. “[In] the coming days, the Senate will vote to take up the House bill with the first amendment in order being what a majority of the Senate has already supported in 2015 and that was vetoed by then-President Obama: a repeal of Obamacare with a two-year delay.” The proposition is largely symbolic: Republicans only supported the full repeal measure in 2015 because they were assured that their effort would be stymied by President Barack Obama’s veto. Now, with “clean repeal” predicted to increase the number of people without insurance by some 32 million over the next decade, the bill is almost certainly dead on arrival.

The only way forward, it seems, is to start over again—potentially with Democrats. “The Congress must now return to regular order, hold hearings, receive input from members of both parties,” said Senator John McCain, whose absence from Washington after undergoing surgery was one of the factors that led to the collapse of the G.O.P. bill. Democrats have said that they will not help to repeal Obamacare, but are willing to work on cross-party amendments. Senate Democrat leader Chuck Schumer wrote on Twitter: “This second failure of Trumpcare is proof positive that the core of the bill is unworkable.”

The latest failure of the health-care bill will not be the definitive end of the Republican effort to supplant Obamacare, but it might signify the demise of the circuitous tussle that has been fought for the past six months. Despite McConnell’s attempts to appear muscular, the overarching certainty is that this is a significant setback for his party’s political agenda and a P.R. nightmare too. In the words of Trump himself: “If the Republicans have the House, Senate and the presidency and they can't pass this health care bill they are going to look weak.” Now, so does he.