Douthat addresses it:
[I]n a country facing a continued unemployment crisis and a looming deficit crunch, liberals have rallied behind a White House whose only real jobs program is "stay the course" and whose plan to deal with long-term deficits relies on the woefully insufficient promise to tax the 1 percent. When Obama insiders wax optimistic about what a second term might bring, they mostly talk about pursuing legislation on climate change and immigration yet again, without explaining why things will turn out differently this time around.
This lack of a plausible vision, more than his stutters and missed opportunities, is what doomed the president in last week’s debate. His responses to Romney were strikingly backward-looking — alternating between "we’re already doing that" and "we tried that under Republicans, and it didn’t work," and rarely pivoting effectively to "here’s what we should do next."