It should be obvious by now that the battle between John Kerry and the organization known as "Swift Boat Veterans for Truth" (SBVT) has nothing to do with what, exactly, John Kerry did or did not do in Vietnam. The actual accusations about his service record are for the most part exceedingly minor--at worst, that Kerry wasn't quite as heroic as he has claimed, and may have exaggerated his bravery a touch. The sole accusation with any potential substance is that Kerry later claimed to have been in Cambodia, when in fact it's doubtful that he ever was.
But the reason for this accusation's significance is precisely that it calls into question Kerry's political record, not his military one. For while Kerry may have used his claimed military heroism to burnish his character credentials, he later used his claimed runs into Cambodia to buttress his political positions as an antiwar activist and politician. Similarly, most of the SBVT animus towards Kerry, judging by their public pronouncements, is a product of his antiwar activism, not the petty details of the episodes that won him his medals.
However, SBVT dare not make Kerry's antiwar history the issue itself, for the simple reason that their staunch belief in the justice and honor of that war is far from unanimously shared among voters. Were they to assail Kerry as a hippie pinko radical traitor, they would run up against a great deal of opposition from people who considered Kerry's antiwar stance a principled and justifiable one. Indeed, there's no guarantee that such a debate wouldn't earn Kerry more support than it loses him. So instead, SBVT call Kerry a liar--and who can argue in defense of lying?
Of course, SBVT hardly invented this tactic. Anti-Bush partisans prefer to call him a liar, a fool or a corrupt dictator rather than discuss the nuances of Iraq policy--on which Kerry has a hard time defensibly differentiating himself from Bush. Similarly, former president Clinton's haters accused him of corruption, dishonesty, immorality, even murder--anything but bad policy choices, since his policy decisions were for the most part highly popular. These days, only unsuccessful politicians get the honor of being attacked for their unpopular political positions. The rest are subjected instead to withering personal attacks, calculated to rally the faithful and perhaps win a few stray fence-sitters, while alienating nobody but the hard-core partisans who are already invested in the attacked candidate's manifold virtues.
The success of such attacks, however, is far from certain, and ultimately depends on the strength of the attacked candidate's political support. Bill Clinton, for example, was pummelled by a series of far more devastating shots--alleged draft evasion, Gennifer Flowers, and others--yet survived to beat an incumbent president basking in the triumph of a spectacularly successful war. His secret: a detailed, brilliantly crafted policy program that allowed him to dismiss personal attacks as insubstantial compared to the "real issues".
Kerry, on the other hand, has been light on policy proposals, choosing instead to run largely on the theme, "I'm a war hero"--and, more generally, "I am not George W. Bush". And because the politician who lives by "character" dies by character, the SBVT attacks have exposed a clear vulnerability in Kerry's campaign strategy. If I were Kerry, I'd be instructing my advisors to come up with some surefire, voter-pleasing new campaign promises--and quick.