I've already referenced the huge throng of folks I personally know or listen to, who did vote for Obama (for whatever reason, be it anti-Bush, pro "hope and change", wanting new leadership, caught up in the "1st Black president", etc), but are so disenchanted, if not disgusted, at what he has done, they'll vote for Romney in a hearbeat, and Newt, only if they had to.
Bottom line is Obama only has his base of hard core leftists, and even many of them are disillusioned because he didn't go left enough in Obamination Care, or closing Gitmo, or a whole host of other leftist causes. That's why you have Obama completely ignoring his record as president, and trying to make this election about personality, and "fairness"
But you are right, "it's the economy, stupid". And if the economy has some recovery, despite the gasoline Obama thru on it, he'll get relected. If it continues to tank & unemployment remains stagnant, it'll be a GOP President with a likely GOP Congress
BUT..................I would NOT be surprised if Obama launches some pre-emptive military attack on Iran's nuclear sites, using likely the "same intel" Bush used to take us into Iraq. The difference being it'd likely involve far fewer troops, but be an ongoing act, necesistating a need to "rally around the President, in a time of war". I'm just saying......I would not be surprised, especially if his poll #'s stay as bad as they are