1. I'll be moving just before it, and will probably not qualify for residency anywhere.
2. The more I study economics the more I realize my vote doesn't matter.
3. The more I study politics the more I realize the system is designed to ensure my vote matters as little as possible.
4. Studying politics has also taught me that 95% of the president's job is to constantly wave his arms to keep the media distracted from the (frankly criminal) activities of congress. (Clinton and Bush were both really good at this by the way).
5. I think I would lose respect for myself if I actively endorsed either candidate by voting for them.
But if I do decide to vote for one of them, this will be why.
Obama: I was an Obama supporter for the majority of the primary season. I liked many of his speeches (I know you can't trust a candidate to follow up on his message, but at least if the message is good you can justify the vote in two years as being "hopeful"), and both of his biggest criticisms (Being elite, and politically inexperienced) are qualities I want in a president. I also liked his pledge to get rid of all those terrible homeland security executive orders.
Then, last May, the new FISA bill came up before the senate. This bill ratified and authorized the removal of most of the rights the aforementioned executive orders took away, and also provided criminal immunity to all the phone companies that helped Bush with all the illegal spying. A couple democratic senators attempted a filibuster to ensure it wouldn't pass, but Obama, along with most republicans and many democrats voted to overturn the filibuster, and then passed the law. That pretty much killed any hope I had he'd be good.
The only bright side I see for Obama now is that, since congress will likely remain controlled by democrats, if he is elected democrats will squabble about priorities while the republicans do everything they can to sabotage their agenda. That should keep them from doing anything too horrible(Most of the crazy things Bush got passed in the last four years failed repeatedly when the republicans controlled congress for exactly this reason).
McCain: I didn't like McCain the first time he ran, and I don't like him now. His decision making process is based far too much on morals and very little on fact, and he doesn't seem to care about domestic issues at all. I'm afraid he will do something crazy like bomb Iran or invade Syria, and I know congress won't have the guts to stop him.
The bright side for McCain is twofold. First off, if the republicans win again, I think (hope) a large number of people will become disillusioned with the system(As a person who is, admittedly, disillusioned myself, I think this is a very good thing as it presages change...eventually).
The second reason is Palin. Regardless of anything else I think a female vice president would be very good for the country, even better than a black president. I think this because the President receives a constant stream of criticism no matter what he does. If he's black, a lot of people will whine that the criticism is racist, and a lot of other people will whine that the other people are whining. That interplay will offset, if not outweigh, any gains we get from actually electing him in the first place. Vice presidents don't get much attention though (Cheney is an exception to this, and even he isn't covered all that much), and more importantly don't make many decisions that can be criticized. I'm sure that dynamic will still be in place, but on a much smaller scale, and not enough to offset the fact that we elected a female vice president (and in the republican party too! That makes it so much better!)
Really though the thing that makes me most likely to decide to vote is if the news networks decide to add Bob Barr to the debates. I know it's pretty unlikely, but one of them just conducted a poll that showed 55% of people wanted it. Why would they ask if they weren't at least considering it?