Former White House aide Cassidy Hutchinson’s Tuesday testimony ought to ring the death knell for former President Donald Trump’s political career. Trump is unfit to be anywhere near power ever again. Hutchinson’s resume alone should establish her credibility. The 25-year-old had already worked at the highest levels of conservative Republican politics, including in the offices of Sen. Ted Cruz (TX) and House Minority Whip Steve Scalise (LA), before becoming a top aide for former Trump chief of staff Mark Meadows. In short, Hutchinson was a conservative Trumpist true believer and a tremendously credible one at that. She did not overstate...