Not since Fox News sued Al Franken over his rip-off of their trademark on “fair and balanced” has anyone committed such a tactical blunder as Senator Kerry and the Democrats bringing in legal heavies to threaten broadcast stations that want to air the advertisement by the Swift Boat Veterans for Truth.The advertisement features veterans who served on Shallow Water Inshore Fast Tactical boats in the Mekong Delta, asserting that Mr. Kerry lied about Vietnam and betrayed the Swift boat sailors who carried America’s cause into those dangerous waters not so long ago.

It is a devastating advertisement that deserves to be seen by every voter before they go to the polls. It should have been been fully anticipated by Mr. Kerry when he chose to base so much of his campaign on his service in the Navy, while dodging and weaving about his role, after the Navy, in an anti-war movement whose most common coin was assertions that American GIs were committing war crimes in Indochina. In 1971, Mr. Kerry himself made such accusations in testimony before the Senate, following his collaboration in an anti-war show trial bankrolled by Jane Fonda shortly before she made her infamous visit to the enemy capital at Hanoi.

Now we well recognize that there are two sides to this story. Many of the antiwar protesters saw themselves, and were seen by others, as acting from a patriotic impulse.We would never suggest that they be blocked from airing their views in advertisements on television or newspapers or anywhere else. But there are certainly just as many who were and are appalled at the things the young John Kerry said before the United States Senate while many of our own GIs, airmen, and Navy pilots were being held in enemy prison camps in Hanoi.This issue doesn’t resonate for everyone, but it resonates for many of us, and the Swift boat veterans who want to challenge Mr. Kerry have every right to do so.

What an insult to the veterans of Vietnam that the general counsels of Kerry-Edwards and the Democratic National Committee are sending around a letter — which we first saw when it was distributed on the Internet by the crusading newspaper Human Events — trying to bully television stations not to air the advertisement. The letter is full of dark hints of legal troubles to come if they do.Surely some television stations will be committed enough to the spirit of the First Amendment to air these important ads.

Senator McCain wants President Bush to distance himself from such ads. It might be good advice for the president; it might not. But the essential point was made by a retired admiral, Roy Hoffmann, the head of the Swift Boat group, who was quoted by the AP as saying they respected Mr. McCain's right to express his opinion and hoped he extends to them the same respect.These veterans deserve the right we all have to speak.