While Jeb Bush feuds Donald Trump and others kowtow to him, only one candidate is seriously gaining on him. Ben Carson is now tied with Trump in one Iowa poll and is close in others, an especially notable result given that The Donald has jammed a lifetime's worth of free media into the past couple of months. Carson's rise suggests that it's possible to catch the populist wave roiling Republican politics and yet not be an obnoxious braggart who abuses anyone who crosses him and will say or do anything as long as he's getting attention. Ben Carson is a...