Who wants a quick lesson in communications theory? Our friends at Rasmussen Reports put out a press release last week arguing that media coverage of Bill White is more favorable than that of Gov. Rick Perry. Shame that stat doesn't actually mean what it looks like it means.

Of course, the marginal right is now jumping up and down, shrieking about media bias. But there are two basic problems. One, this ignores the fact that the "favorable" coverage may come not from intrinsic political bias, and two, there's a major field of research that shows that the favorable/unfavorable coverage equation is totally meaningless.

It's called agenda setting theory: Developed in no small part by UT professor Max McCombs, it debunked the "Magic Bullet" idea that positive coverage in the media automatically transfers to a positive view in the readership. What agenda setting has proven, time and again, is that it's not how the media talks about something, it's how much it talks, that affects popular interest in an issue. There are various factors that affect the process (whether people feel the issue has any relevance, or if they feel they are already informed) but there's a strong correlation between volume of coverage and reader interest, and a much smaller link between editorial line and reader opinion.

Arguably, the more important stat is buried in the press release: That Perry gets more media coverage (eight times the amount of mentions White does). However, agenda setting also posits that it's rare for reader interests to go down that low. So, in this case, it wouldn't be whether voters back Bill or Rick, but instead about whether they care that there's an election going on.