(Bloomberg) Republican Senator Susan Collins of Maine is ready to start over with the health-care debate. John McCain is back home indefinitely in Arizona fighting brain cancer. 

Republicans can only lose two votes and still pass their embattled health bill, with several other Republicans undecided over whether to proceed. Even so, Majority Leader Mitch McConnell of Kentucky says the Senate will vote early next week on, well, something related to health care.

Collins said Thursday she has “no idea” what that will be.

The party has lurched in recent days between giving up on repealing Obamacare and restarting talks over a new Trump administration proposal aimed at winning over moderates. Next week could be a key test over whether Republicans have any chance at delivering on their seven years of promises.

Almost all Republicans still say they want to get to "yes." But that path has remained stubbornly elusive, as the GOP confronts estimates that its bill will leave millions more Americans without health insurance.

“If you’re still going to take more than $700 billion out of the Medicaid program, I still have significant problems,” Collins said.

Seeking Repeal

Conservatives are still pushing for a more complete repeal of Obamacare, and are happy to push ahead with McConnell’s break-glass-in-case-of-emergency plan to repeal Obamacare with a two-year delay.

Related: Trump urges senate GOP to delay recess to repeal Obamacare

“I’ve been advocating that we repeal Obamacare -- all of it,” Senator Rand Paul, a Kentucky Republican, said this week. 

Whether that vote can succeed remains in doubt as negotiations continue on a replacement.

Senate Republicans weren’t helped by a Congressional Budget Office analysis Thursday that found McConnell’s latest proposal would cause 22 million Americans to lose their health insurance in a decade, the same as his last plan that didn’t gather enough support. The nonpartisan budget office also found that the Senate bill, called the Better Care Reconciliation Act, would raise costs for many people with private coverage and slash Medicaid spending.

At the same time, the CBO said the Senate bill cuts the U.S. budget deficit by $420 billion by 2016, an increase from $321 billion forecast under the previous version of the bill. That could provide GOP leaders added funds to bump up health expenditures and attract support of some moderate holdouts.

Negotiations Continue

Talks continue over possible changes, with more than 20 undecided Republicans attending a Wednesday night meeting with Health and Human Services Secretary Tom Price, and conversations continued with McConnell Thursday. Holdouts include Rob Portman of Ohio, Shelley Moore Capito of West Virginia, Mike Lee of Utah, Lisa Murkowski of Alaska and Jerry Moran of Kansas.

One change under discussion, which has attracted interest from pivotal Republicans like Bill Cassidy of Louisiana, would provide extra funds to states to help move some low-income people from Medicaid to private insurance plans. Seema Verma, the head of the Centers for Medicare and Medicaid Services, proposed that idea to some GOP senators on Wednesday, Alaska Senator Dan Sullivan said. Sullivan said Verma called it a “wraparound” plan to provide extra help on the individual market for poor people.

Her plan seeks to partially replace Obamacare’s cost-sharing subsidies that lower out-of-pocket costs for people making between 100 percent and 250 percent of the poverty level. The current GOP health bill would end the Obamacare subsidies. Details of Verma’s plan haven’t been made public, and it isn’t clear that there’d be enough funding in the bill to help all the low-income people who would leave Medicaid maintain similar coverage to what Obamacare provides.

Cassidy told reporters Thursday that “empirically it works,” and that his understanding is that as much as $200 billion may be allocated to fund that.

Possible Revolt

Even as some moderates examine the idea, Republican leaders still risk a revolt by Ted Cruz of Texas and some other conservatives. They’re insisting on the inclusion of Cruz’s proposal to allow private insurers to offer policies free of Obamacare’s consumer protections alongside plans that comply. It remains unclear whether the provision will be allowed under expedited procedures Republicans are using, or whether it will be removed by opponents who say its promise of cheaper plans would pull too many healthy people out of the exchanges.

Some lawmakers are changing positions frequently, making the outcome of next week’s votes hard to gauge.

Paul shifted course and told reporters Thursday that he would vote with his party to allow the health-care debate to begin when a critical procedural vote comes as early as Tuesday, so long as he’s guaranteed a vote on a full repeal. He made clear he still doesn’t back the GOP’s leadership replacement legislation.

“If they want my vote, they have to at least agree that we will have a vote on clean repeal,” he said. He said that as long as that proposal gets “equal billing” with other alternatives on the first day of debate, he’ll help let the leaders bring their bill to the floor.

Senator Bob Corker, a Tennessee Republican, on Thursday for the first time said he would support a repeal of Obamacare “after a reasonable transition period.” It is a marked shift for a senator who has called for a clear replacement, and who successfully lobbied Republican leaders to keep Obamacare’s tax increases for the wealthy in their replacement plan.

Republican leaders, who have said they want to begin work on a tax overhaul rather than prolong the health debate, say they’re determined to hold their vote next week, regardless of the outcome.

Senator John Cornyn of Texas, the No. 2 Republican leader, told reporters Thursday that if the measure fails and McCain is absent, the legislation can be reconsidered when he returns.

“If we fail by one vote, we can come back to it when he is available,” Cornyn said. “There is some benefit to going forward next week to see where we are, and that may be the outcome.”

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