Arizona Sen. John McCain’s opposition to the Graham-Cassidy Obamacare overhaul bill has dealt a near deathblow to Republicans’ frantic last-ditch effort to repeal Barack Obama’s signature healthcare law after years of promises.

Republican Senate leaders have not announced they are nixing plans for a vote next week on the bill spearheaded by Sens. Lindsey Graham of South Carolina and Bill Cassidy of Louisiana. But McCain’s decision left leadership with few options in trying to cobble together 50 votes for the measure, with Vice President Mike Pence casting the tie-breaking vote.