If you just can't bring yourself to vote for Kerry--you might dislke any number of things about him or just feel unsure of him or have bought into the idea that a Democrat is a certain sort of a person and you're not so you just can't vote for a Democrat--don't vote for Bush. And if it means you not voting, I can live with it.
If you don't vote, you can still complain. Complaining is a fundamental human, pre-human, and non-human right, recently guaranteed by the First Amendment. Your odds of getting listened to are fair-to-middling, and not dependent on whether you vote.
I'm not doing any sort of emotional blackmail around this election. I do not intend to lose any friends over it (though it's hard when I get really pissed at someone's reasons as well as their choice).
Now for some reasons for not voting for Bush. My reasons center on civil liberties. The American justice/penal system was already pretty bad (I can't see the difference between a plea bargain and a coerced confession), and I don't think we can afford an administration which is philosophically committed to the idea that it's ok to disappear people--to hold them indefinitely without naming or charging them. It doesn't surprise me that people so held are kept in bad conditions or that whether they are any danger to the US wasn't investigated promptly. Don't kid yourself, being a US citizen will not protect you against that sort of thing if it's standard practice.
Niemoller's quote ("first they came for the Jews/Communists/trade unionists) doesn't have the edge it should because it's about people who are now either respectable or at least semi-ok. Try it as "first they came for the drug dealers and terrorists" and I think you'll get more of the point.
Now we get to Abu Graib. While it's a natural outgrowth of the way a lot of Americans think about prisoners (if you're accused, you're guilty, and if you're guilty, whatever treatment you get is your own fault), it was an enthusiastic and especially stupid application of those theories.
Unqualified Offerings (page down to "faithless electors") has a fine rant on the evils of war. It's not just a matter of the war being pursued incompetently. I will add a small point. We've gone ballistic over 3,000 dead out of a population of 300 million. Is it entirely reasonable to expect Iraqis to be good sports about at something between 5 and 33 times as many dead out of 27 million?
Still, incompetence is more fun to write about. Here's one that may have gone past you in the recent news overload. Josh Rushing was the Marine who was featured in the movie The Control Room.
Since the link is to a longish chunk of audio, here's a summary. Rushing was a Marine, and intelligent and dedicated. What he wasn't was an expert on Iraq. Much of what he knew about the country he learned from _Iraq for Dummies_ which he read on the plane trip to the country. He didn't know Arabic.
As junior officer, he was given the job of speaking for the US to Al Jazeera, a major news source for some 45 million Arabs. He wasn't even given his own translator. Now, this isn't the fog and hurry and desperation of war. This is the people in charge just not bothering to pay attention.
When Rushing showed up in The Control Room (when he was interviewed for the movie, he thought it was just a student project and had no idea it was going to be shown at Sundance), he was given orders not to speak about it, and to tell his family not to, either. His family didn't obey, and he got so frustrated with not being allowed to defend the military (many people who saw the movie interpreted him as a lone voice of sanity), he left the Marines.
Bush is the President who doesn't think he'd do anything differently in Iraq if he could do it over. Please don't vote for him.