The past 50 years have not been good for presidential impeachment. In 1974, the Constitution worked as it should have when President Richard Nixon resigned on the brink of certain impeachment in the US House of Representatives and conviction in the Senate. With substantial proof of Nixon’s misconduct assembled by the House, Senate and special prosecutor, the public overwhelmingly agreed with removing Nixon from office. In contrast, Republicans last Wednesday voted to authorize an impeachment inquiry into President Joe Biden based on unspecified, undemonstrated misconduct. There is no evidence, much less any established public consensus, that impeachment is warranted or...