It's simplistic, but this is strategy. There is a great space in the public mind that is filled with the one line description. It is foundational psychologically, it affect even you and I more than we'd like to admit.
Instead of letting the opposition cast the one line idea people have, make your own. You have to. The candidates try but do they understand themselves the right way? what the one liner really has to address? It has to address the sort of impression you get if you watch these candidates speak for just a few minutes for the first time. Address that to keep their mind open.
Dean: Emphasize he is a New England Patriot... that's the old country, they have the original kind of patriot round there.
Kerry: Trustworthy. Why? Booming voice. Get him a radio program on the new liberal station, a rumor will do.
Lieberman: He's Independent. Amazingly, even conservatives think he's ok. (None of these have to be true, truish will do)
Edwards: Mill Worker's son, becoming a lawyer was "makin' good" (message: not a lawyer really... good guy). Also not actually 35. (two sentences)
Gephardt: Start a rumor he's going to have a celebrity in his cabinet. Emphasize connections.
Clark: Four star general rhodes scholar. (pssst: no dead american soldiers due to bosnian conflict...)
PS: And all you ones out there that can not stand the Clark idea do not overlook a Cheneyesqe arrangement where the VP actually drives policy more. You need a frontman after all which is not just a figurehead in some arrangements. One that can meet with foriegn leaders, etc., make final decisions as arbitor between staff and analyst.
Clark is a good enough chief adminstrator and many of the other candidates have good policy ideas.