The cable news networks Saturday aired a moving speech by Rep. John Lewis at the 50th anniversary of Bloody Sunday in Selma, Ala., ostensibly as they waited for the “headliner,” President Obama, to take the podium and deliver his address. Some might say it should have been the other way around; Lewis spoke from an experience that Obama never had — something made clear by Lewis’ Twitter account, which enhanced his speech with photos from the time.