For Donald Trump, politics and entertainment are intertwined and often synonymous. His remarkable success at both makes his latest missteps especially puzzling because Trump is committing the cardinal sin of both: He’s become boring. The ultimate shock jock is now predictable. Wind him up and watch him throw a garbage can full of insults at anyone who won’t kiss the ring. Ho-hum. Florida Gov. Ron DeSantis and Virginia Gov. Glenn Youngkin are getting the Trump treatment now. Both are rising Republican stars, so naturally the former president trashes and demeans them. Can’t be competition for top dog. Long gone is...