I said that voting for third parties wouldn't help. Even if you cost them elections, the math works out so it's foolish for Democrats to move left to appeal to you. Pulling the American public left to you, so the Democrats can take up your view and win, is the only thing to do.
Dadahead's response focuses largely on criticizing this assertion of mine: "Assuming a normal distribution of voters across each of the political/philosophical axes, moving left puts [Democrats] at risk of losing the people in the center, and there are way more voters in the center than on the edges." I think he'd say that my caveat -- "Now if you have some reason to think that there isn't a normal (bell-shaped) distribution on your issue, this analysis may not apply." -- is applicable to lots more cases than I think it is. He accepts that we're in the minority with regard to parental consent laws and gay marriage, though I think we both agree that our pro-gay stance is a great investment for the future.
To pick just one issue, there is enormous support in the political 'center' for government-guaranteed universal healthcare, a paradigmatically 'progressive' issue. The same goes for rolling back upper-class tax cuts, keeping Social Security, avoiding unnecessary wars, etc.
I agree with dadahead, his friends at the DLC, and John Kerry that rolling back Bush's tax cuts for the rich is something to push for without hesitation. Against Bush's Social Security Death Star, Han and Lando have put aside their grievances, the shields are down, and the Millenium Falcon has flown into the core reactor shaft. When this fight is over, we're going to have a big Ewok party on Endor with New Democrats kissing Deaniacs while the ghosts of Obi-Wan and Franklin Roosevelt smile upon us.
Serious health care reform, however, is an issue on which we've got to do a lot of work to persuade Americans to our side. They'll love it once everyone gets nice cheap health insurance, but irrational fears of government interference in the economy will make them fear it until they have it. We'll be up against an insurance industry fighting for its life. Americans only love government programs that already exist, and the insurers will make our proposal seem like the scariest piece of socialized medicine ever. I don't believe we have the power yet to win this fight, though I'd be really happy to be proven wrong. In any case, I see this as the time for people like us to lay the groundwork. (If anyone can sell health care reform in the near term, I think it's John Edwards.)
And then there's Iraq. Look, if everyone had seen in advance how it would turn out -- no WMD, no terrorist links, terrible management, the destruction of American soft power, a medium-term crippling of the American military, huge costs, Iraq becoming Jihad University, an interminable military commitment, so many dead -- Republicans might have nixed it themselves. (Sure, most of them won't say that now. They don't have the courage to flip-flop.) The Democratic wing of the Democratic Party was right on this all the way. But questions of retroactive political strategy are not easy here. After an easy-looking campaign in Afghanistan, and after earlier successes in Bosnia and Kosovo and a disastrous non-war in Rwanda, Americans simply didn't think things would go wrong in war. For years, they had been taught that Saddam was the biggest villian on earth, and they were terrified by 9/11 and anthrax. Could we have convinced them that this wasn't going to go well? (I wouldn't have expected Bush to screw things up so badly either. I mean, I thought he'd do a bad job, but the sheer botchery that has occurred is pretty phenomenal.) I suppose we could've tried a "finish Afghanistan first!" message. Or maybe we could have made our strong stand, gotten slaughtered at the polls in '02, regrouped, and won in '04 with a pure and clear message. Who knows?
I really don't see myself as a liberal or a centrist, as these intra-party disputes go. I'm just a utilitarian, trying to avoid the Pundit's Fallacy, and playing the hand I'm dealt.