Newly elected House Speaker Arthur Lira suffered his first legislative defeat last week. Members of the lower house failed to reach an agreement to vote on a constitutional amendment that would shield federal lawmakers from arrest and other criminal consequences. Despite promising to respect congressional rules, Mr. Lira tried to go over lawmakers’ heads and force a floor vote on the controversial proposal.
Under normal circumstances, constitutional amendment bills must be analyzed by a special committee before going to a floor vote. Mr. Lira hoped to skip this step and take it straight to a final vote, but failed after...