And the third reason is that conservatives are neither as stupid nor as memory-enfeebled as the Romney campaign seems to think swing voters are. Conservatives haven't forgotten the pre-debate Mitt Romney, the self-described "severely conservative" pol.
So maybe the emerging conventional wisdom is accurate and Romney is as unbeatable post-debate as Obama was beforehand.
Or maybe conventional wisdom is too tactically focused and so prone to missing the big picture, an argument political scientists have been making for months or more. Middlebury College professor Matthew Dickinson, for example, noted this week that the roughly dozen political science forecast models have projected Obama taking a slight majority of the popular vote. "If the mean forecast model is correct, Obama will win by a far smaller margin than what the national tracking polls were saying for most of September," wrote Dickinson (a former professor of mine). Obama's September lead was overstated but by the same token the Romney lead that has Democrats so panicked is likely inflated as well.
Step back and the big picture—including the makeup of the electoral map and the relative resources each campaign has put into ground game organization—remains brighter for the president than the challenger.