What's More Important--Being a Good Progressive or Being a Good Democrat?

I have to say that I'm more than a little intrigued by the prospective candidacy of Mayor Michael Bloomberg in the 2008 race for the presidency. Don't get me wrong---I'm still rockin' for Barack all day long, but Obama has a 1 in 3 chance to be the Democratic nominee at this point, if you believe in the current tiers of the race.
Here's what we as Democrats might be faced with next year:
Hillary Clinton vs Mike Bloomberg vs Any of the JackAss Repugs running. Obviously, none of us are going to run to the Dixipublicans, but we'll have a real dilemma in left vs center battle. And, in my view, our Democratic nominee would represent the center.
Bloomberg is pro-choice, pro-gay marriage, very green, anti-unilateralist, and sees politicians like himself as elected to solve problems---kinda like post-election Schwarzeneggar. And when we have people who run government believe in using the government to solve the nation's biggest problems---well, isn't that what progressives are all about?
Another thing to ponder---is it treasonous of me as not only a Dem voter but a local Dem officer to be having such blasphemous thoughts? I've been straight blue for as long as I can remember, but there's no doubt in my mind that I would cast a vote for Bloomberg over Clinton and others should they get the nomination, maybe even others considered more liberal than Bloomberg. I'm tired of the polarizing, and things need to get done. The planet is in crisis, and so is the nation's health. We need solutions. So, while I think Obama has the chance to be a generational leader, in the FDR/Kennedy tradition, I don't have that same belief about others.
Should I resign my position in the party now, or wait to see if BHO wins or not? In my heart, I'd like to think I know I'm progressive first, Dem second.