The widely applauded decision to name a special counsel won’t resolve some momentous matters raised by the Russia affair. Robert Mueller’s investigation is limited to considering criminal acts. His purview doesn’t include determining whether Trump should be held to account for serious noncriminal misdeeds he or his associates may have committed with regard to his election, or violations of his constitutional duties as president. The point that largely got lost in the excitement over the appointment is that there are presidential actions that aren’t crimes but that can constitute impeachable offenses, which the Constitution defines as “treason, bribery, or other high crimes and misdemeanors.”

Vote-splitting has had a profound influence on many presidential elections. Because it reduces vote-splitting, majority rule would encourage more major candidates to run in the general election.