The national madness known as "McCarthyism" began 60 years ago in Wheeling, W.V., when Joseph R. McCarthy held up a scrap of paper that supposedly listed the names of 57 State Department officials he said were actually Communists and traitors.

Eventually, America learned that the Wisconsin Republican's famous list was a fabrication, that he was a liar and a demagogue as well as an alcoholic -- and that his authoritarian appeals to fear were worse than useless in defending our security.

But by then, McCarthyism's self-serving and fundamentally unpatriotic promoters had inflicted grave damage on the body politic and international prestige of the United States.

Today, McCarthy's heirs are more slick and glib than he ever was, yet their fundamental methods are the same. When Elizabeth Cheney, William Kristol and their media friends slander Justice Department attorneys as the "al-Qaida 7" and malign the "Department of Jihad," they are engaging in the smear tactics that became synonymous with McCarthy.

What is different now is the cynical hypocrisy of the new McCarthyites, who know that the flimsy accusations they level against Democrats in the Obama administration could just as easily be turned on Republicans who served President Bush.

Cheney and Kristol have charged that certain lawyers in the Justice Department represented alleged terrorists held at the Guantanamo Bay prison camp -- and that by so doing, those attorneys rendered themselves unfit for government service.

"Whose values do they share?" asks an ominous advertisement aired by their front group, known as Keep America Safe. They mean to insinuate that the values of those Justice Department attorneys, President Obama and Attorney General Eric Holder are somehow closer to the jihadism of al-Qaida than to those shared by most Americans.

The values that most of us share include honesty and fairness -- and this sleazy campaign violates both. If every lawyer who represents someone accused of terrorism is by definition a terrorist sympathizer, then our entire system of justice is in doubt, since it requires counsel for everyone accused of a crime. More specifically, if the lawyers who have counseled terror suspects are by definition untrustworthy, then the dark cloud of suspicion extends well beyond the current roster of the Justice Department -- and into the heart of the Republican Party.

As Scott Horton points out in Harper's magazine, the McCarthyite list would have to include Michael Chertoff, who headed the Justice Department's criminal division before President Bush nominated him as secretary of the department of homeland security. Among Chertoff's clients in private practice was a New Jersey doctor named Magdy el-Amir, identified as a conduit for money-laundering to al-Qaida and other jihadist outfits.

He became a Chertoff client when the state of New Jersey sued him to recoup illicit money from a health maintenance organization he controlled, which had sent more than $5 million by wire transfers to bank accounts "where the beneficial owner is unknown." In other words, a very dubious character who had been under surveillance by the FBI for years.

There was never any reason to believe that by representing Magdy el-Amir (who was recently arrested in a prescription drug racket), Chertoff somehow disqualified himself from government service. But similar phony questions could be raised about Michael Mukasey, the former Bush attorney general whose law firm provides pro bono representation to Guantanamo detainees. Or Rudolph Giuliani, the mayor of Sept. 11, whose firm has also represented detainees because, like all prisoners, they are entitled to counsel.

If this seems confusing, here's a simple principle to keep in mind: Representing someone in an American court does not mean agreeing with that person's actions or ideology. Here's another: Guilt by association is an unworthy tactic that ought to raise suspicions about those who use it rather than those against whom it is used.

The career of McCarthy and the specter of McCarthyism ended only when a handful of decent Republicans -- notably including Prescott Bush, the grandfather of George W. Bush -- joined in a Senate resolution of censure against him and his tactics. Perhaps we have witnessed such a moment of truth this week, when 19 prominent Republican attorneys, including Kenneth Starr and several former Bush Justice and Defense Department appointees, denounced the Keep America Safe smears as shameful, unjust and destructive.

Conservatives can effectively discredit this disgraceful campaign -- and it is their responsibility to do so.

Joe Conason writes for the New York Observer (www.observer.com).