John Kerry is in a box. He's been calling on President Bush to denounce the Swift Boat Veterans for Truth ad, although Bush's more generalized blast at independent "527" groups yesterday makes it harder to press that point. But what are Kerry's possible arguments for dismissing the Swift Boat ads?

1. It's Ancient History. This is the easy and logical response to attacks on something a politician did 30+ years ago under factual circumstances that have grown hazy: dismiss it as old news. Heck, Bill Clinton routinely called for people to "move on" from things he'd done while he was President. Indeed, even the Vietnamese think that the Vietnam War should be a non-issue in this campaign. But Kerry torched that bridge a long time ago; a man who introduced himself to the general electorate in July and made his Vietnam service literally the first thing out of his mouth, surrounded by his "band of brothers," can't plausibly argue that what happened in Vietnam means nothing to his campaign.

2. Independent Ads Are Bad. Given the vast array of anti-Bush spending over the past year - including Michael Moore pushing his movie's video release up to October - Kerry can't well denounce 527 groups and other independent actors in principle.

3. It's Wrong To Attack A Man's Service Record. Here's the biggest problem: if Kerry wants to stand on principle as saying you shouldn't attack a man's service record, he has a three-pronged problem: (a) he himself is attacking over 200 of his own comrades who are involved in the Swift Boat campaign; (b) he has to deal with his own past history of making false charges of widespread atrocities against American troops in Vietnam; and (c) he has personally attacked Bush's service record with the Texas Air National Guard. From Kerry's own mouth:

I think a lot of veterans are going to be very angry at a president who can't account for his own service in the National Guard, and a vice president who got every deferment in the world and decided he had better things to do, criticizing somebody who fought for their country and served

That was accompanied by this Kerry campaign press release entitled "Key Unanswered Questions on Bush's Record In National Guard." And, from Kerry's campaign spokesman, Chad Clanton:

Voters are going to have to decide: someone who volunteered to service their country when their country needed them or someone else who, you know, it speaks for itself. It is a contrast, it is a difference. … There is no better test than whether someone is committed to defending their country than whether they've put their life on the line on the battlefield.

Were Kerry to take the same stand he demands from Bush, he'd have to denounce himself and his own campaign. Oops.

4. Attack The Financing. This has been Kerry's main tactic: focus on the Republican financiers of these ads rather than the men in the ads. Of course, Charles Krauthammer had the best response to this:

The Democrats have reacted to the Swift boat vets with anguished and selective indignation. This assault was bankrolled by rich Bush supporters, they charge. No kidding. Where else would Swift boat vets get the money? With the exception of the romantic few who serially marry millionaire heiresses, Swift boaters are generally of modest means. Where are they going to get the cash to be heard? Harold Ickes?

Anyway, unlike Paula Jones - about whom the charge may have had some credibility - people can't seriously believe that the 200+ Swift Boat Veterans, each one a man who served his country in wartime, have been bought off; they may or may not be the most credible individuals, but most of them seem to be gainfully employed, and some quite successful.

5. They're Lying. Of course, this is the bottom line, but it's a place Kerry doesn't want to go, because it means engaging the Swift vets on their terms: disputing whether the accusations are true. But it's all he has left, and now - with the campaign focusing on Kerry's anti-war activities, about which the only dispute is how clear it should have been to Kerry that his charges were untrue - even that is not a defense.