Contrast those with the case of the Swift Boat veterans, whose thoroughly discredited accounts of John Kerry's Vietnam service have been treated with respect and whose book is now a best seller. While Kerry has repudiated an ad made by MoveOn.org that ridicules Bush and Dick ("I had other priorities") Cheney for skipping a war they hypocritically favoured, Bush has repeatedly refused to do the same on his side, which gives the news media license to take the whole thing seriously. Bush told The New York Times last week that he thought Kerry was telling the truth, but he still wouldn't denounce the ads attacking Kerry as a liar. (His call for a ban on all "527" independent ads is a transparent dodge.) So much for any sense of decency. The man who was once an inept right-wing president but a nice guy is now just an inept right-wing president.

Of course, Bush's nastiness is in the tradition of Alexander Hamilton and Thomas Jefferson, who used surrogates to accuse each other of sexual improprieties, and scores of candidates who followed. For all the hand-wringing, going negative works, as Bush's uptick in the polls indicates. So if playing rough is just part of politics, why are the Democrats so much worse at it? Even when they win, Democrats never quite close the toughness gap.

One example: Ten years ago, Kerry briefly considered supporting a 50-cent-a-gallon gas tax, then withdrew the idea. Bush now has an ad up savaging him for it. Three weeks ago, Bush floated his own trial balloon favouring a national sales tax. When he withdrew it, the Kerry campaign said, "Oh, OK," and declined a chance to air ads blasting the president for planning to tax every shopping trip to the mall.

Part of the explanation lies in the DNA of the two parties. When FDR's critics lambasted him as a "dictator" and "traitor," he responded with brilliant humour, lampooning the GOP for going after "my dog Fala." But his Democratic heirs mostly lacked either the light touch or the instinct for the jugular, which is one reason so few have made it to the White House. In the last half century, every Republican ticket except one has contained Richard Nixon, Bob Dole or one of the Bushes, all of whom proved expert with the shiv. (The one exception, 1964, is not coincidentally the only time Democrats, led by LBJ, played rougher.)

Usually the toughness gap is the Democrats' own fault. Because liberals are temperamentally self-critical, they tend to see more grays than black-and-whites. Republicans are better at closing ranks. If Kerry were the GOP candidate this year, hardly anyone in his party would be trashing him privately or predicting defeat, as some Democrats are doing.

A related contrast comes in the way the parties address their own constituencies. Republicans offer "red meat," a sense that they share the resentments of their audience. Democrats, schooled in political correctness, tiptoe around their friends, ever anxious not to offend. This conditions them to be more defensive and reactive toward their enemies.

The year 2004 was supposed to be when Democrats found their fighting spirit. Howard Dean's early success convinced Kerry and the rest of the Washington Democrats that only a feisty, give-'em-hell campaign had any chance of success. But Kerry's one tough race, against moderate Massachusetts Gov. Bill Weld in 1996, may not have fully prepared him for the task. While Clinton faced real conservatives in the Hobbesian world of Southern politics, Kerry hails from a state where Michael Dukakis was seen as a tough guy.

If Kerry loses, the Washington Democratic establishment may be done, too. Fire-breathing liberals, mirror images of the ideologues on the right, will take over the party, likely dooming it to yet more defeat in a country that is fundamentally moderate. Kerry can prevent that by finding his voice and finally crystallising his indictment of Bush in a few words that voters can actually remember. None of them need be about the Vietnam War.

(c) 2004, Newsweek Inc. All rights reserved. Reprinted by permission.
Jonathan Alter is a senior writer for Newsweek.