I doubt Obama will lose, just because Romney is so damn unlikeable. People forget how badly the left hated W in 2004. I doubt the left has hated a sitting president more than W in our history, the only other option is possibly Nixon, and it didn't do a bit of good if the candidate you have to vote for doesn't inspire you.
Kerry was much more suited to be President than Romney, had much more experience in politics and was a war hero. Romney has nothing going for him, it's why none of his personal attributes poll well. What he has is the unhappiness towards Obama, but sitting Presidents don't get ousted by boiler plate candidates.
Sure Reagan beat Carter and Clinton beat Bush but neither sitting President inherited a bad economy, they started a bad economy whereas no one can claim that today's economy is worse than the one that Obama took office in. Also, Reagan and Clinton energized their bases because their bases loved them, no one loves Romney.
The Jobs numbers are bad, but they don't matter as long as we're gaining jobs each month and not losing them, Romney won't have an answer.
During the Debate:
Obama: We've been gaining Jobs for the last 3 years since I took office. It took me one year to prevent the next Great Depression and stabilize the free-fall, and we've been growing ever since. The government revenue losses at the state and local level have caused a lot of public sector workers like teachers and police officers to lose their jobs, if we hired them all back, we'd be at 7% or less.
Romney: That's not good enough, We're still in a recession, I can get us out of this mess.
Obama: By doing what
Romney: Republican principles
Obama: Well that strategy led to this mess so that won't work, what else ya got?
Point is, as long as we're gaining jobs, All Romney can do is say "I can gain more jobs"...and once he's asked how, all Obama has to do is finish with that last line. Or he has to support things Obama supports like stimulus, hiring public workers, or infrastructure and Obama can point it out by saying something like.
"Well if you're going to run on my agenda I'll take that as a compliment, imitation is the sincerest form of flattery"