If rebel conservatives and establishment Republicans in the House can agree on anything, it's likely supporting Paul Ryan for speaker. Across the Sunday talk shows, members of the Freedom Caucus that helped drive Speaker John Boehner toward retirement said they could swing behind Ryan in the wide-open race for a successor. That's what Boehner and his allies want, too. But the fragile, theoretical consensus falls apart over just how the speaker should wield power. Freedom Caucus members want major changes in how the House works, including shifting some power from their speaker to committee chairmen. The ideal speaker, these conservatives...