Yes, it was one of the biggest sweeps in history. Yes, many of the normally Democratic supporting voters stayed home.
While I think it's pretty safe to say that most of the voters that stayed home did so because of Obama, his performance and his liberal policies. Or perhaps the perception of Obama's policies being liberal.
I think it right that liberalism's brand has been damaged through all this, fairly or unfairly, I don't know. What I do know is that the ever greater statism that liberal policies require certainly hasn't gained any fans. No one seems to want to have an excessively intrusive, excessively intervening, all powerful state redistributing health, picking winners and losers, and that, from my perception anyway, is the cornerstone of today's liberalism.
Seems to me, keep the classic liberal, dump the statist liberalism, and I'd be more OK with that.