Paul Ryan has signed off on a letter promising restless members of the House Freedom Caucus (HFC) that he won’t bring immigration-reform legislation to the House floor while President Obama remains in office. The letter, obtained exclusively by National Review, formalizes pledges that Ryan made last week in a closed-door meeting with select members of the HFC who were skeptical of his promise to maintain an “open” and “inclusive” relationship with the caucus. Specifically, it extracts Ryan’s word that he will not bring up comprehensive immigration reform “so long as Barack Obama is president” and, as speaker, Ryan will not...