With the House set to impeach the president on Wednesday, there is no real reason that a full-fledged and scrupulously fair trial cannot begin the very next day in the Senate. This is not a complex case factually. Audio of Mr. Trump’s call to Brad Raffensperger, the Georgia secretary of state, is in the public record. So are the president’s videotaped words inciting his supporters to march on the Capitol. The violence that followed was on television for all to see.

Nor is the law hard to understand. High crimes and misdemeanors, impeachable offenses enumerated in the Constitution, are crimes against American democracy. Mr. Trump’s incitement of an insurrection qualifies, without question, as an impeachable offense.

The Senate’s majority leader, Mitch McConnell, has said that he cannot commence an impeachment trial before Jan. 20, unless all members of the Senate agree to allow it sooner. In fact, as Chuck Schumer, the minority leader, has suggested, in emergency situations, the rules allow him and Mr. McConnell to reconvene the Senate immediately. Removing from power at once a president who has incited an attack on his own government certainly qualifies as an emergency situation.