I'm concerned about what it means for science. We've already witnessed the political vetting of science advisors, censorship of politically unfavourable reports (esp. regarding environmental issues), and the spreading of lies to further the conservative agenda (e.g. against condoms and abortion). I doubt it will get any better - and it may well get worse, if the Bush administration carries out their threat to punish scientists for speaking out against them during the campaign. The American Journal of Bioethics blog offers a more specific forecast.
I'm concerned about what it means for secularism. The separation of church and state in America appears to be eroding. Faith-based initiatives, spending millions on intercessory-prayer studies, the increasingly-vocal "Intelligent Design" movement... Bush senior once said that atheists should be considered neither citizens nor patriots - you surely couldn't get away with saying that about any other minority group. America may be becoming a "Christian nation", a nation where atheists are persected and even killed for their (lack of) beliefs. Bush's re-election brings America one step closer to that theocratic dystopia. (I hope I'm just overreacting here, but religious extremists really scare me - Christians no less than Muslims.)
Most of all, I'm concerned about what this election result means for morality. People are saying the key issue in this election was "moral values", and that this overwhelmingly favoured Bush. That's really scary. It suggests that there's a large portion of the American populace whose moral compasses are completely fucked up. (A point made more eloquently at Obsidian Wings.)
The ultra-conservatives brought us Abu Ghraib. They sent an innocent Arab-Canadian to Syria to be tortured, and they've tried to pass a bill to make this common practice with terrorist suspects. They're even better at killing Iraqi civilians than was Saddam Hussein.
But geez, I guess none of that compares to the horrors of gay sex. Bigots turned out in droves to enforce their twisted values. Now they can rest safe in the knowledge that marriage has been protected from those who want to marry. (Though I do have a bit more sympathy towards those who oppose abortion, the other big conservative 'moral' issue. I think their position is misguided, but at least not evil.)
Many have noted that we can't blame Bush anymore. He was chosen by a majority of voters. We'll have to change them instead:
Ultimately we will have to fight values with values. I honestly think we have to figure out a way to convince more rural, heartland Americans to think like good secular liberals -- i.e., to come to celebrate (or at least accept) differences in race, sexual preference, religious belief, and so on. (I said it wouldn't be easy.)
Crooked Timber discusses whether Democrats should instead make more concessions to religion (and conservative religious values). I hope it doesn't come to that.
On a more positive note, at least Bush will have to deal with the consequences of his own mistakes (especially the mess in Iraq, and the huge economic deficit). Though some have suggested that conservatives will still find a way to blame the liberals anyway.
P.S. Go read Timothy Burke's take on the 'moral values' issue. It's the best post-election post I've seen yet.
Update: Fafblog is brilliant as ever:
FB: Now everybody up til the election thought the biggest issues were gonna be Iraq an the war on terror but funny thing, it turned out it was more important to stick it to gays. Huh! What do you guys think about that?
FALWELL: Well if you think about it, homosexuals ARE a sort of terrorist, Fafnir. Terrorists... of the family.
FB: Not the family! That's where we keep all our babies!
JESUS: [bursting in] Stop, stop! This is obscene!
FB: Jesus, please. We already did your interview.
JESUS: [overturning interview tables] I told you to love your neighbors as yourselves, not withhold their civil rights! I said blessed are the peacemakers, not the warmongers! I said my kingdom was not of this earth, not to make laws and bribe officials and overrun governments in my name!
DOBSON: Can you please have security remove this man?
[FB:] Why does Jesus hate America?