Rep. Pete Stark (D-CA) and uberliberal called the more conservative Blue Dog Democrats "brain dead." Seriously, he is quoted as saying that, not suspected or repeated by someone else.
The problem with such a strategy is that these conservative to moderate Democrats have the ability to kill the legislation in the House. Ticking them off doesn't seem like a strategy that is designed to win. Particularly when the Blue Dogs are probably much more representative of most American's viewpoints on teh matter than Pete Stark is.