Cassidy Hutchinson’s Testimony against Trump Is Devastating

Cassidy Hutchinson, a top aide to Trump’s White House chief of staff Mark Meadows, provided compelling testimony Tuesday that former president Donald Trump is singularly culpable for the Capitol riot.

The testimony in a session of the House January 6 committee — a session abruptly called, reportedly due to concerns about Ms. Hutchinson’s safety — was devastating because it was directly about the former president. The day’s lone witness pulled back the curtain that countless advisers and aides kept around the mercurial Trump for four years. There are significant questions about aspects of...