The backbenchers are heading into another box canyon now. Mr. Boehner is undermined because the other side knows he lacks 218 GOP votes, which empowers House and Senate Democrats. They want to reverse the modest spending discipline of the sequester, and if the House GOP can’t hold together on the CR they will succeed. The only chance of any entitlement reform worth the name is if Mr. Boehner can hold his majority and negotiate from strength.

We’ve often supported backbenchers who want to push GOP leaders in a better policy direction, most recently on the farm bill. But it’s something else entirely to sabotage any plan with a chance of succeeding and pretend to have “leverage” that exists only in the world of townhall applause lines and fundraising letters.

The best option now is for the GOP to unite behind a budget strategy that can hold 218 votes, keeping the sequester pressure of discretionary spending cuts on Democrats to come to the table on entitlements. The sequester is a rare policy victory the GOP has extracted from Mr. Obama, and it is squeezing liberal constituencies that depend on federal cash.