It’s been a week of shocks, failures and gaffes, different in severity but all revealing.

In Washington Rep. Kevin McCarthy, presumed successor to Speaker John Boehner, seemed to be acting out what he understands to be the anger and aggression of the GOP base. He’s grim-visaged, stern. He says “frustrated” a lot. I guess when you’re not sure what substantive moves on-the-ground Republicans desire, you go to stylistic concerns. Mr. Boehner usually opted for an easygoing, humorous dignity that sometimes required a certain verbal...