This is not news to anyone, of course, but it bears repeating. At least in the TV age, i.e. starting with 1960, and with the possible exception of 1968 which was a special case, the more likeable candidate has ALWAYS won the election.
Liberals live in a reality-based world, where facts and arguments matter. But it's an useful exercise, although less pleasant than pulling teeth, to switch all this off and watch the debate like an 'undecided' voter does. They haven't been paying attention, and they don't hear the facts in any case. They absolutely hate argumentation. What matters is warm feelings---who do they like best? You might be proposing to send all poor people to the gas chamber, but if you say it nicely, it's all okay.
Until 2 weeks ago, Obama was well-liked personally, while Romney seemed somewhat smarmy. That's the big advantage Obama pissed away---it's not a matter of whether he called Romney out on all the lies.
Romney says he ran a business but his job was not to make payroll, get a product out the door, and so forth. What he was is a rainmaker, a pitchman, and a very effective one. The biggest problem with being a salesman is that you get used to saying whatever will make the sale, including different things to different audiences, and that doesn't always work in the YouTube age. But the biggest advantage is that you learn how to pitch the sale, and we saw Romney do that in the first debate.
Obama has to do better today. He has to leave the 'undecided' (low information) voter feeling warm and fuzzy all over...it's like romancing your spouse all over again. He's got to make those voters feel a thrill up their legs. Unfortunately, while Obama's smile is still high-wattage, but it doesn't always seem to reach his eyes nowadays. He seems tired, the easy seduction isn't there, we've been married too long.
He has to do better today, but what logical points he actually makes don't matter at all.