Sometimes Presidential campaigns need no help at all descending into farce.Let's say, for example, a candidate lets himself get pulled into a debate over whether he really deserved all three of his purple hearts while running against an incumbent who's most perilous wartime assignment, according to military documents, was showing up for a dentist appointment. That kind of scenario only comes about by divine (read: Rovian) intervention - or total PR incompetence. Then there are times you need to make your own comedy and lighten the mood to remind folks how out-of-hand things have gotten. That's when the pros turn to Comedy Central. Or at least that's what the Kerry camp did. Reeling from the attacks of his fellow veterans, which only seemed to grow louder as the accusations grew older, John Kerry defused the situation - slightly - with a lighthearted turn on The Daily Show, Comedy Central's increasingly legitimate "fake" news program. In truth, the tack was two-pronged: Sympathetic vets were dispatched to defend Kerry and attack the attackers, while the candidate went on late-night TV laughing about the incident with a predictably befuddled-by-the-whole-thing Jon Stewart. If nothing else, it did what all good PR does in an unwinnable crisis: It changed the subject. Nothing Kerry was saying on his own was knocking the media off the story, but what network can resist a clip of a chronically stuffy candidate awkwardly yukking it up? The morning after the show, the swift boaters were practically MIA, but clips of the show were hard to miss. It may have been a temporary respite, but it gave Kerry a chance to stop the bleeding - from a wound no one could claim wasn't serious.