I voted for Obama because he was -quite sadly- the lesser "evil" of everyone running. Yes, third parties included. Once they reach the national stage of a presidential election, anyone still around is going to be a "bad" choice by virtue of what's required to get that far. With that in mind, Obama seemed to, at the very least, have the best intentions, if not necessarily the best plan. He also seemed the most likely to move towards the center, should the balance of power ever split (as it did with the mid-terms...and, as evidenced by the number of Democrats pissed off with him since the mid-terms, he is doing just that.) All that being said, had I been the same person in 2008 that I am today, I likely would have just stayed home.
That's not a troll, nor is it hair splitting: that's plain honesty.