The GOP bill, which would replace the ACA’s subsidies with less generous tax credits while repealing its insurance mandates, has run into opposition from across the political spectrum. Aside from the Chamber of Commerce, most industry groups have lined up against it. And despite the president’s hearty support, conservative activists and the billionaire Koch brothers say it falls far too short of a full repeal and have vowed to punish Republicans who support it.

Perhaps the biggest challenge for Republicans is that the bill as written appears to lack any defined constituency in their districts. A Quinnipiac University poll released on Thursday found just 17 percent of respondents supported the American Health Care Act based on what they had heard about it, and opponents outnumbered those in favor by a three-to-one margin. That would make the plan far more unpopular than Obamacare was even at its lowest point. But it jibes with what conservative critics in Congress have reported: For every call they receive in support of the bill, hundreds of constituents are urging them to vote it down. “The people back home are not sold on what we’re doing yet,” Representative Pete Sessions of Texas, chairman of the House Rules Committee, said Wednesday on CNN.

Late Thursday afternoon, the Congressional Budget Office released a revised estimate of the GOP bill’s cost after amendments were added earlier in the week. The nonpartisan scorekeeper found that the changes to Medicaid and tax policy would cost nearly $200 billion more over a decade than the original bill, but they would have little effect on insurance coverage or premiums. The CBO is still estimating that 24 million fewer people would have health insurance by 2026 and that average premiums would rise in the first couple years after the passage of the bill before falling by about 10 percent over a decade.

Depending on how many lawmakers vote, Republicans can lose no more than 21 or 22 votes on their side and still achieve a majority. Democrats will vote en masse against the bill. Public whip counts put the defections at well over that number, but party leaders can still cross the threshold if they flip the group of conservative opponents led by Meadows. The bill would still need to pass the Senate, which would be an even more Herculean task for GOP leaders, considering they have a narrow, 52-48 seat majority and several Republicans have also declared the House plan unacceptable.

In a scene reminiscent of the fiscal showdowns of the Obama years, lawmakers spent most of Wednesday and Thursday waiting in their offices awaiting news of a deal. One member of the Freedom Caucus, Representative David Schweikert of Arizona, even wandered over to Ryan’s office in the Capitol Wednesday night to ask the assembled reporters what they heard. When they told him there was no news, he began pitching them on his own plan to fix the nation’s health-care system, which the leadership had ignored. On Thursday, another lawmaker could be overheard complaining that she would have to miss a trip to Disney World if the vote was delayed a day.