It could turn out that Obama has a plan to kill 10 million innocent people, and he'd still get re-elected. GWB was re-elected, and he had quite a few scandals and 'black sheep' associates.
Thinking that a specific story about Obama would prevent him from getting re-elected implies that voters look at issues objectively and will vote against candidates with character flaws. Our political system and voting procedures are based simply on one question: "Who will keep me living in this illusory world of material gain with the least amount of work and sacrifice for the longest?". As of right now, I think Obama still has a pretty good chunk of voters believing that he actually knows what he's doing. Some people are catching on to the fact that he's got no clue what he's doing, but they unfortunately don't have much of a choice for a better candidate, so they will either not vote, or just stay with the ignorance they already feel comfortable with. I think that's also a reasonable explanation as to how GWB got his 2nd term. seekliberation