Having George W. Bush question your military record must feel not unlike having Anna Nicole Smith question your intelligence. Surely, there is a weightless moment of disbelief, a struggle with a level of gall that just does not compute.

Yes, I know the White House has denied any connection between the erstwhile Texas Air National Guard fighter pilot who sits in the Oval Office and the so-called Swift Boat Veterans For Truth, the group that has accused Democratic presidential candidate John Kerry of inflating his Vietnam war record. In a TV ad and a best-selling book, the boaters claim Kerry never plucked a fellow sailor from the water while under enemy fire, never chased down and killed an armed Viet Cong soldier, never was seriously wounded by the enemy, never was a hero.

John Kerry has denounced the group as a front for the Bush campaign. The campaign has denied having anything to do with the boaters. We are indebted to the Washington Post and the New York Times, among others, for revealing what a grandiose fib that is.

Turns out the group is financed in part by a longtime associate of Karl Rove, the president’s chief political adviser. One Bush campaign official — he resigned Wednesday — provided the group with legal advice. Another left the campaign after it was revealed that he had appeared in the offending ad.

There are other examples, but you get the point.

Of course, the damage has already been done. Despite the fact that John Kerry has medals and wounds attesting to his valor as a swift boat commander, despite the fact that military records and the men who were there support what he has said, despite the fact that some of those now criticizing him previously went on the record lauding Kerry’s courage, despite all this, the issue of the swift boats has managed to inflate into a controversy. Some conservative commentators would have us believe there is really some doubt about what Kerry did in the waterways of Vietnam.

Critics, including Republican Sen. John McCain, have pressed the president to denounce the ad. Bush refused to do more than call for an end to all “third party” campaign advertising until announcing Thursday that he would join a lawsuit “to shut down all the ads and activity” by these groups.

I tend to be skeptical about such advertising myself, but the president’s response is specious. The issue here is not ads, but ad — a specific campaign from a specific group.

In one sense, I suppose we shouldn’t be surprised at Bush’s refusal to speak ill of the swift boaters. After all, they serve two purposes for him. One, they smear mud on his opponent. Two, they divert the electorate’s attention from matters the president would doubtless prefer we not focus upon too closely.

Or does anyone really think swift boats are the most important issue of this campaign?

Every hour spent debating what happened in Vietnam over 30 years ago is an hour not spent debating what’s happening in Iraq right now. Not to mention Afghanistan right now, the economy right now, the environment right now, the schools right now.

Yes, politics is a dirty business. Yes, third party groups and candidates from both major parties spend millions on advertising designed to make the other candidate look like an ax murderer. Still it seems to me that some things are simply beyond the pale.

This is one of them.

I have never been in combat. Until a few weeks ago, I had never heard of a swift boat. But I have profound respect for the men and women who wear the uniform of this nation and go into harm’s way when duty calls. As far as I’m concerned, you do not impugn that service lightly, no matter what your or their political affiliation might be.

It’s a matter of honor.

His apparent inability to understand that speaks volumes about the president’s own honor or lack thereof.

Leonard Pitts Jr., winner of the 2004 Pulitzer Prize for commentary, is a columnist for the Miami Herald.