I'm not sure I understand, but this writer is an idiot.
Seriously, if all the "intellgent liberals" are screened out, explain DU?
Heck, one time a few weeks ago, Rush had a liberal caller right at the top of the second hour, and the caller asked Rush if he could take as much time to make his point, Rush gladly gave him the floor, and at the end of his 10 minute "monologue" the caller said "thanks for wasting my time", hung up, and Rush sounded confused and asked Snerdley if they called him.
Funniest radio I've heard in YEARS!
Easy, there are no intelligent liberals.