The latest in-party bickering amongst liberals - Bill Maher/MSNBC v. Jon Stewart - highlights why the left can't sustain a consistently persuasive narrative for the voting public and thus win elections. Progressives spend much of their time arguing amongst themselves on degrees of differences in opinion, rather than focusing on what they do agree on and using that to counter and correct the right-wing echo chamber.
In-fighting amongst Democrats mirrors the divisive nature of unions in our country. The splintering into various factions over the past few decades, squabbling over petty territorial or policy perspectives, has decreased the reach, power, and effectiveness of unionization (alongside a completely anti-union legislative landslide). The conflicts from within are also weakening the Democratic party. At their best, unions and the Democratic party went hand-in-hand. Both, now, seem to be following a self-mutilation strategy.
So, to wrap up, it's time to focus on the big picture, Democrats. Flesh out the minute details once you've secured power. Focus on the most important issues and deliver the message we can agree on (rather than the details we can't). We're being beaten by the kid who eats his own boogers right now. This isn't the time to be criticizing our allies over style points.