T esla CEO Elon Musk called President Joe Biden “a damp sock puppet in human form” on Twitter Thursday as Tesla stock plummeted 11%. Musk’s lack of restraint on social media is, as the saying goes, a feature not a bug, having landed him in legal hot water multiple times. Another Musk tweet—“Biden is treating the American public like fools”—was part of a one-sided Twitter offensive waged against the president. Biden didn’t retaliate, at least not directly. The White House did post a tweet with the president extolling Tesla rivals General Motors and Ford for their work on developing electric...