Republicans plan a fresh bid to push their health care bill through the House of Representatives and claim a victory for Donald Trump, six weeks after nearly leaving it for dead.
The change of direction also comes days after support from Republican moderates seemed to crumble anew.
House leaders plan a vote today on the legislation, revamped since collapsing in March to attract most hard-line conservatives and some GOP centrists.
In a final tweak, leaders were adding a modest pool of money to help people with pre-existing medical conditions afford coverage, a concern that caused a near-fatal rebellion among Republicans in recent days.
"We will pass this Bill," House Majority Leader Kevin McCarthy predicted.
The bitter health care battle dominated the Capitol even as Congress prepared to give final approval to a bipartisan measure financing federal agencies through September.
The House passed that on Wednesday 309-118, and Senate passage seemed certain as early as Thursday. That would head off a weekend federal shutdown that both parties want to avoid.
The health care vote was scheduled after the White House and congressional leaders piled pressure on those resisting.
A wafer-thin margin seemed likely, thanks to opposition expected from every Democrat and more than a dozen Republicans plus lobbying against the bill by the AARP, doctors, hospitals and patients' groups.
On Tuesday, one count had 21 Republicans saying they would oppose the bill - one short of the 22 defections that would kill it if all Democrats voted no. Many others were undecided.
House approval would edge Republicans closer to repealing much of former president Barack Obama's health care law, which would represent at least partial redemption of campaign pledges by GOP candidates - including Mr Trump - since its enactment in 2010.
Passage would also send it to an uncertain fate in the Senate, where some Republicans consider the House measure too harsh.
Polls have shown Mr Obama's much-maligned law has gained in popularity as the debate over a replacement has accelerated.
"House Republicans are going to tattoo this moral monstrosity to their foreheads and the American people will hold them accountable," said House Minority Leader Nancy Pelosi.
The bill would eliminate tax penalties in Mr Obama's law which hit people who do not buy coverage and erases tax increases in the Affordable Care Act on higher-earning people and the health industry.
It cuts the Medicaid programme for low-income people and lets states impose work requirements on Medicaid recipients.
It transforms Mr Obama's subsidies for millions buying insurance into tax credits that rise with consumers' ages.
The measure would retain Mr Obama's requirement that family policies cover grown children until age 26.
But states could get federal waivers freeing insurers from other Obama coverage requirements.
With waivers, insurers could charge people with pre-existing illnesses far higher rates than healthy customers, boost prices for older consumers and ignore the mandate that they cover specified services.
The bill would block federal payments to Planned Parenthood for a year, considered a triumph by many anti-abortion Republicans.
House Speaker Paul Ryan pulled the plug on a March 24 vote as conservatives opposed the bill for not fully repealing Mr Obama's law and GOP moderates considered its cuts too severe.
That was a jarring setback for Mr Trump and Mr Ryan but leaders have gradually rebuilt support.