I don't know why. Personally, if he ran he would have my support over anything of the people they have now.
Well, he unfortunately got thrown under the bus by the right when he came out with his medicaid and social security plan. He had by far the most aggressive cuts to both programs and most people thought the left would bury him running ads 24/7 telling grandma he was going to throw her off social security. All those ads you saw where grandma was being pushed off a cliff in a wheelchair were attacks on Paul Ryan's plan and scared the shit out of the right. So he got very little support for his plan and quite frankly had no chance this time around. That's just how politics works.
Leave it to leftist to make such a bogus argument. According to the left, if America has soured on Obama, its not because of Obama, its not because of his mesage, its because people are too stupid. Of course, the logical thing to do is look at results, and the Obama economy ain't pretty.