Short answer: bread and circuses.
The bread of government welfare and entitlements.
The circuses of the entertainment industry and media, who have numbed the minds of many Americans, killing their sense of history, their ability to question and think critically, and their ability to distinguish entertainment from real life.
The entertainment industry and media have supported BO without challenge or criticism of any sort. He is the "entertainment President." To borrow from Daniel Greenfield/Sultan Knish, he is President not of America, but of the lazy and the easily entertained.
This election may be a little different from the last one as young voters in some parts of the country that went heavily for Obama are going to have to face up to the fact that the economy hasn't improved and their prospects aren't good. Last time around, young urban voters in New York or California couldn't see themselves not voting for Obama. This time it's a possibility.