So there they are, Paul Begala and Alex Castellanos, on CNN with John Roberts, discussing Sarah Palin's supported-it-before-I-opposed-it lies about the Bridge to Nowhere. And then they actually roll tape of her endorsing the project in a 2006 televised debate. End of story, right? Yeah, right. ROBERTS: That would appear, Paul, to end any argument over whether or not she supported the bridge initially. But why can't Barack Obama make that point stick? BEGALA: Because ...