There have been a lot of questions about why Trump fired James Comey, ever since he announced to NBC's Lester Holt -- incomprehensibly -- that it was his decision, citing, by my count, at least a half-dozen different reasons. On Sunday night, that question was answered. We all owe a debt of gratitude to Comey for showing the American people why he was so badly in need of firing. Interviewed on his new book, "Living in Truth," "The Dictates of My Conscience," "The Politics of Truth," "A Higher Loyalty," it quickly became apparent that one of Comey's favorite formulations is:...