Rick Shenkman takes on some myths. Here’s one of them.

Bill O’Reilly’s viewers are dumber than Jon Stewart’s.
Liberals wish. Democrats like to think that voters who sympathize with their views are smarter than those who vote Republican. But a 2007 Pew survey found that the knowledge level of viewers of the right-wing, blustery “The O’Reilly Factor” and the left-wing, snarky “The Daily Show” is comparable, with about 54 percent of the shows’ politicized viewers scoring in the “high knowledge” category.
So what about conservative talk-radio titan Rush Limbaugh’s audience? Surely the ditto-heads are dumb, right? Actually, according to a survey by the Annenberg Public Policy Center, Rush’s listeners are better educated and “more knowledgeable about politics and social issues” than the average voter.