It shows the difference between an amateur and a pro when Trump jumps up and says “Repeal now, replace later.” Ryan and McConnell have already spent a lot of political capital just shepherding these bills to this point, capital they can’t get back and a loss that will be felt later in the year when it comes time to start dealing with impending deadlines for the budget, the debt ceiling, and other major spending priorities. If this bill dies, then that’s pretty much it until after 2018. No “tax reform,” a much more contentious budget process as the “savings” from Trumpcare will have to come from somewhere else in the budget to fulfill all those promises about “balanced budgets,” and the very real possibility of a government shutdown in the fall.

tl;dr, Yertle has too much invested in this bill to drop it and start again. It’s this or nothing until 2019.