I supported Ralph Nader in 1996 and again in 2000. This year, while I don't support him as a candidate, I will defend his right to run for office - and not just because I'm voting for Bush.
I was with the Green Party for seven years, from 1996 (Nader's first run) thru 2003. I registered Democratic around last spring, but my heart wasn't in it. I lasted about a year with the Dems.
If people like Joe Lieberman and the folks at The New Republic represented the majority of Democrats, I'd stay with them. But they don't.
The problem I'm seeing with the Dems now is, ironically, very similar to how the party looked to me from the Green side of the house: they don't seem to stand for anything except "not being Republicans". Every four years they try to convince you that the world is going to come to an end if a Republican gets into the White House. That was their whole case against Nader - because they couldn't challenge him on the issues or on integrity.
Well, whatever you think about the 2000 election, GWB has certainly not caused the end of the world. The only people whose world has come crashing down have been (a) the Taliban; (b) the Iraqi Ba'ath Party; and (c) their sympathizers and apologists in the West.
Nader isn't running on the Green ticket this year, but he will be running as "the anti-war candidate". Kerry will then be really screwed, because he's trying to take a middle position on an issue where there's no middle ground. The Democrats will scream (again) about Nader stealing "their" votes, but by this point it should be obvious that the Democrats never "owned" those votes in the first place. Ironically, this is an example of the very "entitlement mentality" that conservatives so often accuse liberals of.
I think American politics may end up being reborn as a result of all this. If they are smart, the Democrats could re-invent themselves as a centrist party within the next couple of election cycles. The Greens are strong - I still have a lot of respect for them - and could take in some of the far lefties. This three-party model could produce a much more interesting exchange of ideas than the current "duopoly".
But the Democratic Party will have to ask itself some hard questions first.