For me it was simply because Obama was obviously intelligent. I couldn't do eight more years of dumb, aggressive, simple-minded, close-minded, non-reality based/non-scientific orientation based presidenting. The world is too complex and too scary.
And after hearing John McCain (who I LOVED and was eager to vote for, but that faded fast as the campaign trail advanced) in the last day say Obama should be more aggressive on rhetoric towards Iran's current "let's hope it's a revolution", I'm darn, DARN happy I didn't vote McCain, holy crap.
I worried alot about the experience, but knew he'd surround himself with those who knew, as he had repeatedly demonstrated his ego isn't too big to learn from others.
I really wish that alot of the Obama-haters, instead of listening to media interpretations and small soundbites (I don't care, right or left, doesn't matter), would look at the entire interview and judge for
themselves.
For example, today I got a chance to watch the entire MSNBC interview (the one where Obama swatted the fly).
How can anybody say this man needs a teleprompter

, or that he's not thought far ahead on the complexities of the bank bailouts, the car companies, the economy? Good lord, he's impressive!