There is an important lesson here for us all: How often genuine political promise coexists with puerility and worse. White House press secretary Josh Earnest wasn’t just being diplomatic or clever yesterday when he said he feels sad and sorry for Rudy Giuliani, the former “America’s mayor” who’s been raging like a sidewalk lunatic at President Obama. There actually is something sad about Rudy’s long self-destruction, which began before his disastrous presidential primary bid of 2008. Sad, but possibly instructive to the future sidewalk lunatics among today’s Republican presidential-wannabes. Maybe you had to be with Giuliani at the start of...