But while those hardliners are demanding outright repeal, more moderate Republicans report never being able to support undercutting one-fifth of the American economy without having a backup plan in place.

“We promised repeal and replace, okay, that’s what our promise was. Not just repeal. And those who say repeal is sufficient, in my view, is a betrayal of the promise we made to the American people in 2016,” Sen. John McCain (R-AZ) told The Daily Beast, arguing some in his party are boxed in because they over-promised on the stump. “I didn’t promise it would be easy. Some did, I can only speak for myself, I didn’t think it was going to be easy, particularly in a state that expanded Medicaid.”

By moving the legislation to the right, through phasing out coverage more swiftly for millions of Americans, Republican leaders threaten to lose the support of more moderate Republican senators who are alarmed by the CBO’s projections.

“The CBO estimate that millions of Americans could lose their health insurance coverage if the House bill were to become law is cause for alarm,” Sen. Susan Collins (R-ME) told reporters at the Capitol. “It should prompt the House to slow down and reconsider certain provisions of the bill.”