'Maybe Democratic leaders aren't finding success in expanding their liberal base because fair-minded Americans don't easily gravitate to a political party led by people whose default election tactic is to demonize its opponents..'

Well, of course, the Democrats are the party of hate.

From Tom Bevan: The End of Civil Rhetoric (via Instapundit):

It’s also true that Democrats are under pressure to rev up what appears to be a lethargic electorate or face defeat at the polls in November. It’s unfortunate that we’ve come to accept the idea that voters can only be motivated by fear and anger toward their political opponents.

Yep, that's all they've got.