The House GOP yanked its health-care bill on Thursday ahead of a planned vote, and perhaps they’ll reconvene on Friday or later. But as Republicans contemplate wasting this historic reform opportunity, they should start thinking about the costs and responsibility of failure.

The delay is said to be a defeat for President Trump and Speaker Paul Ryan, but both men have done about as much as they can. They’ve listened to different points of view across a diverse coalition of Members and 33 Governors, and the House bill is a realistic...