The Democratic presidential campaign has been a bust so far.After nearly a year of campaigning, the only one of the nine announced candidates to catch fire has been Howard Dean, whom party leaders deride as too liberal and too error-prone to beat President Bush. That explains the extraordinary welcome that many Democrats yesterday gave General Wesley Clark’s announcement that he was joining the presidential race. The chief boosters of General Clark’s candidacy are none other than William and Hillary Clinton. General Clark hails from Little Rock, Ark., knew Mr. Clinton when he was still a governor, and had an extraordinary...