There's a whiff of desperation in the air over tonight's vice presidential debate—and a hint of controversy, too. The desperation, of course, comes from the blue team, which is desperate to halt the momentum Mitt Romney gained in the first debate, and expects Joe Biden to be especially aggressive in attacking Paul Ryan. The controversy? A conservative site has dug up evidence that President Obama may have attended moderator Martha Raddatz's wedding. Here's what you need to know: