Nearly six weeks after Republican leaders in the House canceled a vote on a controversial replacement for the Affordable Care Act because they lacked the votes, they are set to try again on Thursday.

And California’s 14 Republican members of Congress will be critical in deciding its fate.

House Majority Leader Kevin McCarthy, R-Bakersfield, confidently predicted success after a day of wrangling votes and personal arm-twisting by President Donald Trump.

After the earlier failure, the decision to move forward indicated confidence on the part of GOP leaders. A successful outcome would be the culmination of seven years’ worth of promises by Republicans to undo Obama’s signature legislative achievement — though an “Obamacare” repeal still must pass the Senate, where its fate is anything but certain. And if House Republicans narrowly pass it on Thursday, it could result in political blowback by endorsing a bill that boots millions off the insurance rolls.

That’s what worries congressional Republicans in the Golden State, where Obamacare has been highly successful in driving down the rate of uninsured people. And many residents of poor GOP-leaning and swing districts in the Central Valley depend on Medi-Cal, which was greatly expanded under the Affordable Care Act.

To win this time, the House Republicans cannot lose more than 22 votes among its members because Democrats have stood firmly united against the repeal.

Representatives of seven members of the state’s GOP congressional delegation told the Bay Area News Group on Wednesday that they have not endorsed the latest version of the American Health Care Act, as the repeal law is called, while U.S. Rep. David Valadao, R-Hanford, told a radio station he is also undecided. Representatives of five others said they support the bill, while a spokesman for Rep. Paul Cook, R-Yucca Valley, did not respond to a reporter’s inquiries.

Opposition to the bill continues to mount, with patient advocacy groups, doctors, hospitals and others saying it would slash Medicaid funding by tens of billions of dollars. Opponents also warned that the proposed legislation would jack up the cost of premiums for those people who buy insurance in the individual market — and would even weaken the fiscal sustainability of Medicare.

A major sticking point for some Republican members of Congress has been concerns that the bill didn’t adequately cover the GOP’s vow to protect people with pre-existing conditions — more than a quarter of the U.S. population.

But a last-minute amendment announced Wednesday by two GOP congressmen now adds $8 billion more to the $115 billion already proposed in the bill to help pay for insurance for those Americans. And that may be enough to change some “no” votes to “yes.”

McCarthy has never strayed from his mission to repeal and replace the health care law. Standing alongside him in support are Reps. Mimi Walters, R-Laguna Niguel; Devin Nunes, R-Tulare; Tom McClintock, R-Elk Grove; and Duncan Hunter, R-Alpine.

But Rep. Jeff Denham, R-Turlock, still hasn’t made a decision, according to his spokesman, nor had he reviewed the latest amendment as of Wednesday.

Denham, after all, has something else to consider: After winning his 2016 re-election bid by fewer than 5 percentage points, he is now facing a new challenger from the Bay Area.

Josh Harder, a venture capital investor at Bessemer Venture Partners in San Francisco who has worked in tech and cyber security investments, announced his candidacy for Denham’s Central Valley seat on Tuesday. Harder, 30, a Democrat, has strong connections in Silicon Valley’s VC industry, which could help him mount a well-funded challenge to Denham.

Sources close to U.S. Rep. Dana Rohrabacher, R-Huntington Beach, and U.S. Rep. Ed Royce, R-Fullerton, told the Bay Area News Group they had yet to make up their minds as of late Wednesday. That was also the case with U.S. Reps. Steve Knight, R-Lancaster; Darrell Issa, R-Vista; Ken Calvert, R-Corona; and Doug LaMalfa, R-Auburn, according to their offices.

“We’re seeing some changes being made currently,” said LaMalfa spokesman Parker Williams. “Once we actually see a bill on the floor, we’ll have an update there.” But he noted that his boss still “has a lot of concerns across the board right now.”

The latest iteration of the GOP bill would let states escape a requirement under Obama’s 2010 law that insurers charge healthy and seriously ill customers the same rates. Overall, the legislation would slash Medicaid funds, eliminate Obama’s fines for people who don’t buy insurance and provide generally skimpier subsidies.

The American Medical Association, AARP and other consumer and medical groups are fiercely opposed to the GOP bill. The AMA issued a statement Wednesday saying the latest changes to the legislation “tinker at the edges without remedying the fundamental failing of the bill — that millions of Americans will lose their health insurance as a direct result.”

The Affordable Care Act has helped to provide insurance to 24 million Americans, including 5 million Californians.

California health care advocates warned Wednesday that an extra $8 billion to fund individuals with pre-existing conditions in so-called “high-risk pools” is merely a drop in the bucket — and not likely to cover much of anything for those affected. Health care policy experts say a vital high risk pool would need to be $150 billion to $200 billion nationwide.

“It does little to solve the problem,” said Anthony Wright, executive director of Health Access California. Moreover, California has already dealt with a high-risk pool, “and it didn’t go well,” Wright said.

While congressional Republicans appear to be rushing a vote — without waiting for the bill to be reviewed and scored by the nonpartisan Congressional Budget Office — angry constituents worried about losing their health care coverage have been staging protests across the country outside offices of Republican congressional members.

Over the past three days, the liberal advocacy group MoveOn.org commissioned planes and mobile billboards carrying a “Don’t Take Away Our Health Care” message to fly over the GOP offices around the country, including the California district offices of Rohrabacher, Valadao and Knight.

On Thursday, that same group will be joined by others as they protest outside 20 key House Republicans district offices, including the same three California congressmen, urging them to oppose the American Health Care Act.

“The GOP TrumpCare plan is a disaster,” said Ben Wikler, MoveOn.org’s Washington director. “By rushing this bill through Congress, Republicans are creating a manufactured crisis that will devastate millions of families.”

The Associated Press contributed to this report.