Suddenly, impeachment can wait. Speaker Nancy Pelosi said Thursday she’ll delay transmitting the two House-approved articles to the Senate, in an obvious ploy for partisan advantage. For anti-Trump legal scholars Noah Feldman and Laurence Tribe, that has created a Schrödinger’s Cat scenario. They disagree on whether President Trump has been impeached at all.

Mr. Feldman says no: “If the House does not communicate its impeachment to the Senate, it hasn’t actually impeached the president.” Mr. Tribe says an affirmative vote...