I suppose this is the greatest problem with the Democratic party, is that they are nothing but a bunch of various political groups cobbled together. If Biden tries to appeal to the moderates, he isn't doing enough for the progressives. And if he tries to appeal to the progressives, then he alienates the moderates. It seems his strategy so far has been to talk the progressive talk, but walk the moderate walk, and it doesn't strike me that it's working particularly well considering the polls.<p>The Republicans have this problem to an extent as well, but it seems that the various wings of the party have much less of a problem "falling into line". Whereas the modern progressive insistence on ideological purity makes party cohesion much harder for the Democrats.