In 2000, for many reasons, Nader voters were a factor in the final results. This time around, Kucinich is getting many of those people back into the Democratic party -- for now. But there's still a possibility that Nader or someone else will run as as a Green; Nader has said he'll decide by the end of 2003. (The Natural Law party has endorsed Kucinich already.)
Now, we all know that Kucinich is not going to get the nomination. (And if he somehow manages to, conventional wisdom is that Bush would stomp him.) So what will his supporters do next November?
I think this question is most interesting if Dean is the nominee. Dean's a populist, which Kucinich voters like, but he's a centrist, which Kucinich voters may not like. He's also a Washington outsider, which Nader voters like. Clark is military, which is sure to turn off a host of those supporting the "Department of Peace" candidate. The rest are pretty much the same type of politician as Gore, which may be able get more Green votes this time, or might turn off these voters the same way Gore did.