There's a lot of talk about how divided the Republican Party is, but I'm not sure we're in significantly worse shape than the Democrats at this point. If you don't buy that, take a look at this poll from the Daily Kos,

When 48% of the readers at the Daily Kos believe that, "progressives (should) create a third major political party," it's a pretty good indication that all is far from well with the liberal base.