19x121 - Late Show with David Letterman

Political Twins in History; what's happening at the Convention; the new Obama campaign commercial; our team of political analysts standing by; Biff Henderson at the Democratic National Convention, and a Top Ten list presented by First Lady Michelle Obama. TOP TEN: REASONS TO WATCH THE DEMOCRATIC NATIONAL CONVENTION - and to present tonight's Top Ten list, plausibly live, First Lady Michelle Obama. You know her from the Harry Potter films. She now stars in a new film, "The Perks of Being A Wallflower." Emma spent the summer in Iceland working on another film. She's the host of the CBS daytime talk show, "The Talk". Julie is pleased that Dave is so familiar with "The Talk". Dave's political analysts: insight or incoherent?