WASHINGTON—Senate Republicans are expected to vote as early as Tuesday to begin debate on their sweeping health-care legislation—but they don’t know yet what measure they will be voting on. Some senators said Majority Leader Mitch McConnell (R., Ky.) has told them they would know before the vote whether they would be asked to allow debate on some version of a bill to repeal and replace the Affordable Care Act, or legislation that would repeal the ACA with a two-year expiration date. GOP leaders’ current strategy is to lean heavily on lawmakers to at least vote to allow debate on the bill, in the hopes that amendments and other tweaks could yield an agreement. But the plan carries some risk. If the “motion to proceed” fails, it would mark a defeat for President Donald Trump and congressional Republicans, and could end their current efforts to overhaul the ACA, also called Obamacare, a seven-year Republican campaign promise. There has been little evidence that senators who opposed the latest version of the bill earlier this month have reversed course. Sen. Rand Paul (R., Ky.), a leading conservative, dismissed the Republican bill Sunday on CNN’s State of the Union as a “porkfest” that bails out insurers. He said he would vote to begin debate as long as there would be an opportunity to vote on a repeal measure. Mr. McConnell’s challenge is that with a narrow 52-48 majority, he can afford to lose no more than two Republican senators, with Vice President Mike Pence breaking a 50-50 tie if necessary. Sen. John McCain (R., Ariz.) announced recently he has brain cancer, and the timing of his return to Congress remains uncertain, making the math even more precarious. Mr. McCain tweeted on Friday that he would “support whatever health-care plan” Arizona Gov. Doug Ducey, a Republican, endorses. Mr. Ducey criticized a version of the GOP health plan in June for not doing enough to help his state’s Medicaid population. Republican leaders are urgently trying to win back defectors among the conservative and centrist wings of their party. Negotiations with centrists like Shelley Moore Capito of West Virginia, for example, are focusing largely on possible changes to soften the impact of the bill’s Medicaid cuts, but so far none of the holdouts have announced a change of heart. Sen. Bob Corker (R., Tenn.), who supports opening debate, said recently he was concerned about Republican leaders’ moves to appease the reluctant senators. “It’s feeling like a bazaar, like…. we’re throwing money in a lot of different directions but potentially not moving in a place that’s coherent,” Mr. Corker told reporters recently. Sen. Susan Collins (R., Maine) said on Sunday on CBS ’s Face the Nation that senators had no idea what they would be voting on Tuesday. “I don’t think that’s a good approach to facing legislation that affects millions of people and one-sixth of our economy,” she said, calling for hearings on the bill. Mr. Trump, urging Republicans to unify, tweeted Saturday that “The Republican Senators must step up to the plate and, after 7 years, vote to Repeal and Replace.” The president is traveling to West Virginia on Monday with Ms. Capito, but the audience is 40,000 Boy Scouts and it is unclear if he will talk about health care. Republicans say their effort, which aims to cut back on the ACA’s insurance regulations and significantly cut the Medicaid program, would lower premiums and give consumers more choice. Democrats say it would leave many more Americans uninsured. The nonpartisan Congressional Budget Office estimated that under the GOP bill, about 22 million fewer people would have coverage by 2026 relative to the current law, and a repeal bill would leave an estimated 32 million fewer people insured. Democrats are criticizing both the process and the content of the Republican effort, including the fact that no female senators were included in an initial GOP Senate working group, though Mr. McConnell later broadened the conversation to include all 52 Senate Republicans. Three female GOP senators—Ms. Collins, Ms. Capito and Lisa Murkowski of Alaska—have since emerged as strong opponents of the repeal-only option. “It was a pretty stupid thing to just put men in that room. That likely comes with consequences,” said Sen. Chris Murphy (D., Conn.). Mr. Murphy noted that the women senators’ resistance matched their constituents’ concerns. “Lisa, Susan and Shelley would be your natural opposition to this kind of bill, given the states they come from,” he said. Other GOP women senators noted that not all of them were opposing the procedural motion. “Three out of five. Two of us aren’t,” said Sen. Deb Fischer (R., Neb.), referring to herself and Sen. Joni Ernst of Iowa. Write to Natalie Andrews at Natalie.Andrews@wsj.com, Stephanie Armour at stephanie.armour@wsj.com and Kristina Peterson at kristina.peterson@wsj.com
republican senators are expected to meet as early as 2020 to begin voting on their sweeping health - care legislation — but they do n’t know yet what measure they will be voting on .