Framing that portrays anyone who isn't a corporate raider as "fanatical" might have something to do with the answer.

You might update that storybook for the 21st century and the tea party astroturfers spitting on congressmen.

While this piece is near fanatically left-wing in it's vehemence, many of the basic points and frustrations truly hit home and make me wonder why some of them haven't been said louder. 

The Three Wings of the Republican Party: The Crazies, The Corporatists, and ... The Democrats?