On the health bill, McConnell was left facing an increasingly narrow path, with no apparent way to win over conservative and moderate holdouts seeking to pull the bill in opposite directions.

A sizable group of Republicans from Medicaid expansion states had yet to commit to the bill either, and Lee’s push for a broader repeal of Obamacare’s insurance regulations risked pushing away the votes of senators like Lisa Murkowski of Alaska and Bill Cassidy of Louisiana, who have been among the most vocal in pushing to continue providing protections for people with pre-existing conditions.

A straight repeal bill could look even worse for them. The Congressional Budget Office in January said repealing the Medicaid expansion and exchange subsidies while keeping other Obamacare regulations intact would cause many insurance markets to implode. That would result in an additional 32 million uninsured and premiums roughly doubling, with 75 percent of the country lacking insurers entirely in the individual market in a decade.

Some Republicans said they were ready to redouble their efforts to repeal Obamacare.

“We can because we must. This is kind of a no-fail moment,” Senator James Lankford, an Oklahoma Republican, said Tuesday on Fox News. “Let’s get all the people that disagree in one room and let’s hammer this all out.”

House Freedom Caucus founder Jim Jordan of Ohio told CNN Tuesday that he supported voting on a straight repeal of Obamacare and dismissed the idea that such a bill lacked enough votes.

“If you just went with the conventional wisdom, the underdog would never win,” he said. “So let’s actually put it out there and see what happens when the roll call is really called.”

Democrats immediately blasted the idea. Democratic Senator Chris Murphy of Connecticut called it “a humanitarian disaster of incomprehensible scale.” Writing on Twitter, he said, “Full repeal with no replacement will cause markets to fail. No insurer will stay in an exchange that is disappearing in 24 months.”

Other GOP senators have been talking about a new approach to health legislation, with Lindsey Graham of South Carolina tweeting again Monday about his latest proposal with Cassidy to keep most of the Affordable Care Act’s taxes in place but give states far more freedom on what to do with the money.

McConnell’s plan already was teetering on the brink after Senator John McCain’s unexpected surgery late Friday left him one short of the votes needed to start debate this week. The majority leader had said the bill wouldn’t be considered until McCain returned.