Okay, this is an intriguing new frontier in political media criticism. Media Matters, which has been attacking CNN for not reining in Lou Dobbs’ birther obsession, has now purchased air time to run a TV ad attacking “CNN’s Lou Dobbs problem” — during Dobbs’ show! A Media Matters spokesman tells me the group has bought a week of ad time on CNN, MSNBC and Fox News in D.C., New York, and Atlanta, beginning Tuesday. The catch: Media Matters has specifically purchased time to air the ad during Dobbs’ show — putting CNN in the position of either running the spot...