We are now little more than six months away from the primaries. The real campaign will probably begin on Labor Day, but the Democratic field seems to have organized itself into three tiers. The bottom tier is the vanity candidacies: Al Sharpton, Dennis Kucinich, Carol Moseley Braun. The middle tier is serious candidates who have yet to catch fire: Joe Lieberman (despite high name recognition in the polls), John Edwards (despite financial support from his fellow trial lawyers and some creative speeches about specific issues) and Bob Graham. At the top are John Kerry, the party establishment's favorite; Dick Gephardt, the Midwest labor candidate. And Howard Dean.