Murkowski is getting a hard sell from Republican backers of the bill.

“What I’m trying to figure out is the impact to my state,” Murkowski told reporters Monday. “There are some formulas at play with different pots of money with different allocations and different percentages, so it is not clear.”

Alaska Governor Bill Walker, an independent, expressed concern about the plan’s risks to Medicaid and said individual states should have a chance to weigh in, the Fairbanks Daily News-Miner reported.

"Any proposal to restructure Medicaid goes far beyond repealing the Affordable Care Act," Walker said, adding, "Any proposal to shift federal costs to the states would likely result in drastic cuts to our Medicaid program."

McCain, who is close friends with Graham, cast the deciding vote to sink an earlier repeal bill in late July when he made a dramatic return to the Senate after a brain cancer diagnosis. At the time, he made an eloquent plea for colleagues to work with Democrats and use regular legislative procedures instead of trying to jam it through on a partisan basis.

John Weaver, a former top adviser to McCain, said supporting Graham-Cassidy would require the Arizona senator to renege on his word.

‘Fair Process’

"I cannot imagine Senator McCain turning his back not only on his word, but also on millions of Americans who would lose health care coverage, despite intense lobbying by his best friend," Weaver said in an email. "Graham-Cassidy, if truly attempted to pass, will bypass every standard of transparency and inclusion important to people who care about fair process."

Despite the obstacles, the bill’s backers are putting on a good face about the prospects.

"We’re making progress on it,” said Republican Senator Ron Johnson of Wisconsin. “I’m still cautiously optimistic, but there are a lot of moving parts.” Johnson is planning a Sept. 26 hearing on the measure in the Homeland Security and Governmental Affairs Committee, which he leads. The Senate Finance Committee is planning its own hearing Sept. 25 on the measure.