Gallup's answer is a big fat nope.
The president's very first job approval rating among liberal Democrats was 83 percent, around the inauguration. Today, he's at 84 percent, down from 87 percent at the beginning of 2011.
This would indicate that liberal support for the president has intermittently improved, contrary to what we often read online.
Which is to say, good news. Constructive criticism and rational observations appear to be winning, at least on the far-left of the party.
Whether this translates to enthusiasm during the general election remains to be seen. If liberal turnout is low, we could still have a serious problem -- and strong approval doesn't necessarily translate into large-scale turnout.