Should the goal of the Democratic Party be to nominate anyone who can defeat Bush? Many people think so; I am not one of them. It is true that Bush is the worst president of my lifetime (and possibly of all time). He is ignorant, dishonest, amoral and hypocritical. (He is also not the president; Dick Cheney is, but we have to go with the elected office here.)
The reason I don't think this is a worthy goal is because it is the best example I can think of of sticking a Band-Aid on cancer. The Democratic Party has become so committed to pretending to have Republican ideals that...well, now it has Republican ideals. Clinton, who was never that liberal to begin with, abandoned many liberal principles in order to gain a second term. Look around at your own senator or congressperson: The chances are enormous that s/he voted for the tax cuts, No Child Left Behind, the Iraq War Resolution and the Patiot Act. "Liberal" John Kerry did.
If the Democratic Party had espoused Democratic ideals in 2000, Bush would not have wound up in the White House. If the Democratic Party had thought of--duh--hauling out Bush's record as governor of Texas and forcing the news media to deal with it, Bush would not be in the White House.
When Howard Dean (who is not that liberal, either, but who makes up for it by being authentic) said he didn't want to turn the campaign into a discussion of "God, gays and guns," he hit on the exact tone needed by the party. Instead, the other Democratic candidates crawl around on the floor, hoping to find some rhetorical crumbs that will get them through question-and-answer sessions about gay marriage, the Second Amendment and the very personal subject of religion. Kerry has even gone so far as to say he would "consider" voting for a constitutional amendment to ban gay marriage--the most disgusting thing to yet come out of his mouth.
An incompetent president, corruption in the highest places, lies from the White House, an unnecessary war, out-of-control spending, loss of jobs, a health care crisis, an educational crisis, the destruction of the environment, the erosion of civil liberties...these are pretty good issues, it seems to me. But if you talk too much about them, you may look like you're criticizing the president and the Republican Party. Well, we wouldn't want that.