Quite simply, on election day Obama won't be running against 8 GOP candidates, he'll be running against 1 (and maybe Ron Paul as an independent) with the usual smattering of third party candidates. If the best that Obama has to offer in a year is that unemployment stayed around 9 percent for the last two years of his term, I'd say he would be pretty much done for. He doesn't have much to offer except high government spending, and the best that he can argue about that is the unprovable statement that the economy would have been in worse shape without it.
If much more happens with the Occupy protests, mainstreet America may lash out against the Democrats as well.