After falling short in previous attempts to repeal the Affordable Care Act (ACA), early this week Republican senators lined up behind Senators Lindsey Graham (R-SC) and Bill Cassidy (R-LA) to pass repeal legislation prior to an upcoming procedural deadline on September 30th. However, a Friday announcement by Senator John McCain (R-AZ) indicating his intention to vote “no” on this legislation puts the repeal effort’s future in jeopardy.

This proposed legislation would shift funding of Medicare and Medicaid to the states through block grants, allowing states to devise their own health care systems. Graham-Cassidy would also eliminate the individual and employer health care mandates, end federal subsidies for low-income households, raise caps on health savings accounts, and redefine qualifications for “essential health benefits.” Altogether, cuts in federal health care spending will total hundreds of billions of dollars between 2020 and 2026, with block grant funding phased out entirely after 2026.

The upcoming deadline – set by the Senate parliamentarian – would require only 50 votes from Senate Republicans to pass repeal legislation (along with a tie-breaking vote by Vice President Pence), which could be accomplished by a party-line vote in a GOP-majority Senate. After this deadline, Republicans will be forced to find 60 votes in favor of repeal to advance this legislation, requiring support from Senate Democrats or Independents. McCain’s “no” vote, along with a firm “no” from Senator Rand Paul (R-KY) and expected “no” votes from Senators Susan Collins (R-ME) and Lisa Murkowski (R-AK) will likely sink efforts to call a vote for this legislation.

The Graham-Cassidy legislation will not receive a full score from the Congressional Budget Office (CBO) prior to a potential vote, providing no cost and coverage estimates—a hurdle for previous attempts to repeal the ACA. The passage of this bill in the Senate would trigger a vote from the House of Representatives to pass identical legislation. Should the legislation somehow survive a vote from the Senate, leaders within the Republican caucus expect the House to pass the Senate bill as written, which would send the Graham-Cassidy legislation to President Trump for final approval.