Democracy Corps, the blue-tinged polling outfit that conducts semiannual surveys of how the party's doing, is out with its final 2013 findings. It's a balm for scared Democrats, or at least it's written that way; its authors assume that the negative vibes of the health care law rollout will "fade," and that Republicans will blow every opportunity to rebound. (The poll was conducted before the party punted on the 2013–2014 budget agreement.)
The whole survey is at the link, but these graphs are the ones most likely to make a Democrat think, "Ahhh, much better."
That, I suppose, is what Democrats are supposed to argue for 11 months. Keep them in power and they will nod their heads sorrowfully about what is wrong with the law, and delay or fix the worst bits—not like those other guys, who'll blow it up. One problem with this is that the swing districts monitored by Democracy Corps are significantly bluer than the states where the Democrats need to hold Senate seats—West Virginia, South Dakota, Montana, Louisiana, Arkansas, Alaska. (They're about as blue/purple as North Carolina.)