Shortly before his 21st birthday, Patrick Buchanan brazenly sped by a police wagon on a Saturday night date in Georgetown. When two officers tried to give him a ticket, Buchanan cursed them out, resisted arrest and soon was mixing it up in the back of the wagon, where the policemen beat him with nightsticks. He pleaded guilty to assault and was kicked out of Georgetown University for a year.

Asked about the incident by a reporter years later, Buchanan declared, "I was ahead on points -- until they brought out the sticks."

After a quarter-century of verbal fisticuffs on behalf of Richard Nixon, Spiro Agnew and Ronald Reagan, the man who may be the country's most prominent conservative pundit is suddenly engaged in the nastiest brawl of his career. This time his antagonist is A.M. Rosenthal, former executive editor of the New York Times, who in a column last Friday accused Buchanan of a history of antisemitism, ranging from Buchanan's crack about Capitol Hill being "Israeli-occupied" territory to his impassioned defense of accused Nazi war criminals to his recent remark that Israel is selfishly prodding the United States to obliterate Iraq.

Never one to duck a punch, Buchanan, 51, swung back yesterday in his syndicated column, accusing Rosenthal of a "contract hit" ordered by the B'nai B'rith Anti-Defamation League (ADL). He said Rosenthal had used "the branding iron wielded by a tiny clique, to burn horribly heretics from their agreed-upon political orthodoxy. It is used to frighten, intimidate, censor and silence ... to scar men so indelibly that no one will ever look at them again without saying, 'Say, isn't he an antisemite?' "

Buchanan also called Rosenthal one of "Israel's personal messengers to the New York Times," borrowing a line from the Nation magazine. He further complained about Israel's "gratuitous brutality against Palestinian old men, women, teenagers and children" and about "caustic, cutting cracks about my church and popes from both Israel and its amen corner in the United States."

Rosenthal yesterday called Buchanan's rebuttal "nonsense." He said he decided to write the column as soon as he saw a tape of Buchanan's televised remarks about Israel, and never discussed it with the ADL, although he did consult with author Elie Wiesel and others. "People have been sending me material on Buchanan, Jews and non-Jews, for years," Rosenthal, 68, said from his New York office.

"I don't say all critics of Israel are antisemitic. It's a cowardly position he takes. Often when there is an issue, he brings in the Jews in an extremely unpleasant way. ... I realized I couldn't walk away from this anymore."

Rosenthal's 785 words had the effect of instantly amplifying what had mostly been Washington whispers. Buchanan has long been a lightning rod for controversy, from his assaults on Democrats as the party of Communist sympathizers to his pugnacious defense of Oliver North, but never before has he faced such a damning indictment.

"Although I very rarely use the word 'antisemite,' I must say he comes very close to fitting that category," says Wiesel, a Holocaust survivor. "A man who leaves the memory of Jewish victims in such disdain; a man who always takes the side of those accused of being killers; a man who is constantly criticizing Israel; a man who always has something nasty to say about the Jewish people -- what else can I say about him? I feel there is something in him that is opposed to my people."

While some friends insist Buchanan is no antisemite, others have grown uneasy. "Pat has published a few columns in which he seems to be going out of his way to lump all Jews into the same category," says columnist Mona Charen, who worked for Buchanan in the Reagan White House. "He engenders this kind of thing." While Charen doesn't believe Buchanan is antisemitic, "there's enough evidence to ask him why he's so angry about Jews. Why the suspicion of Jews in this country?"

Buchanan blames the attacks on "a small group" of Jewish leaders who "are going after Pat Buchanan's reputation because they can't answer his columns, his facts and his opinions."

He sees himself as giving voice to arguments that others dare not make out loud. "There are a lot of Americans who are very intimidated from saying candidly what they think about the relationship with Israel. They're afraid of just what's been done to me. They don't want to bring a firestorm on themselves."

For all his proud battle scars, Buchanan concedes he is feeling the heat. "I understand how in the old days people got lynched," he says.

If the story is sweeping through the opinion-mongering world with gale-force intensity, it may be because Buchanan has become a one-man industry since resigning as President Reagan's communications director in 1987. He is said to earn more than $500,000 a year as co-host of CNN's "Crossfire," regular guest on "The McLaughlin Group" and "The Capital Gang," newsletter publisher, syndicated columnist in 180 newspapers and lecture-circuit pontificator fetching fees greater than $10,000 an evening.

"Right now Pat is the most visible and maybe the most important conservative in America," says New Republic writer Fred Barnes, a fellow food-fight panelist on the McLaughlin show. "He's certainly got the biggest megaphone. He's on television at least six nights a week."

All right, Fred, Issue 1: Is Buchanan antisemitic? "If your definition is someone who is personally bigoted against Jews, doesn't want them in the country club, I don't think Pat is that," Barnes says. "If your definition is someone who thinks Israel and its supporters are playing a bad role in the world, Pat may qualify."

Causes Spawn Controversy Any discussion of Pat Buchanan and Jewish concerns inevitably turns to what GQ magazine recently called his "Nazi problem."

Eight years ago, the columnist took up the cause of John Demjanjuk, a retired Cleveland autoworker who was stripped of his American citizenship and extradited to Israel after Justice Department investigators determined he was "Ivan the Terrible," the man responsible for the murders of hundreds of thousands of Jews at the Treblinka death camp. Buchanan became convinced Demjanjuk was a victim of mistaken identity, falsely accused by survivors with faded memories and possibly framed by the Soviet Union, which produced an identification card that placed Demjanjuk at a Polish camp where the SS trained prison guards for Treblinka.

Allan Ryan Jr., former head of the Office of Special Investigations (OSI), the Justice Department's Nazi-hunting unit, calls Buchanan's charge of a KGB frame-up "an absolutely cockamamie theory."

"Buchanan is the spokesman for Nazi war criminals in America," Ryan says. "His campaign on behalf of these people is so infused with distortions and misrepresentations of the facts that it's almost impossible to engage in any sort of response. He simply piles lie upon inaccuracy upon surmise upon personal attack.

"What makes it even more contemptible is that even when he is shown to be wrong, he simply ignores it. ... I think a lot of the stuff he just makes up."

Buchanan insists he is raising factual questions about what may be a monumental injustice. "Ask people: Why do you think Buchanan would undertake this if he didn't believe the man was innocent of the most monstrous crime of the 20th century? Whatever benefit this has gotten me has generally escaped my attention. ... The cause has not exactly been a winner."

Since mounting the Demjanjuk crusade, Buchanan has taken up the cudgels for several others accused of having been Nazis. In July, he compared Arthur Rudolph, a German rocket scientist who admitted in a sworn confession that he had persecuted unarmed civilians, to the late Soviet dissident Andrei Sakharov, calling OSI's case "a fraud" and saying that Rudolph had been "railroaded."

Buchanan suggests that hunting down elderly men responsible for the Holocaust is a distraction from more contemporary concerns. Protesting the U.S. apology for protecting Klaus Barbie from French investigators, he has written: "To what end, all this wallowing in the atrocities of a dead regime when there is scarcely a peep of protest over ... the concentration camps operating now in China and Siberia, in Cuba and South Vietnam."

Last March, a Buchanan column argued that hundreds of thousands at Treblinka could not have been killed by diesel engine exhaust fed into the gas chambers. "Diesel engines do not emit enough carbon monoxide to kill anybody," he said, citing a 1988 bus accident involving Washington schoolchildren trapped in a tunnel. Most experts insist that there is more than enough carbon monoxide in diesel fumes to kill quickly through asphyxiation.

"He was so wildly off it was painful," says OSI Director Neal Sher. "At no time has he ever contacted us about the cases we were handling, even when he was an administration official and he was differing with government positions that were upheld in court. ... He essentially took what was fed him by our opponents, sometimes Holocaust-deniers, and just regurgitated it."

In the wake of these and other crusades, several Jewish organizations began compiling thick files on the columnist, ready to spring into action at the drop of a sound bite. They got their chance late last month when Buchanan discussed the Persian Gulf crisis on the McLaughlin show.

"There are only two groups that are beating the drums for war in the Middle East -- the Israeli Defense Ministry and its amen corner in the United States. ... The Israelis want this war desperately because they want the United States to destroy the Iraqi war machine," Buchanan said on the show.

This drew the fiery broadside from one very prominent Jew, Abe Rosenthal, who accused Buchanan of a "blood libel" against Jews by suggesting they have "alien loyalties for which they will sacrifice the lives of Americans."

ADL Director Abraham Foxman, named in Buchanan's column as an accomplice in the "contract hit," says he sent a release on the Buchanan remarks to Rosenthal and other columnists, but was out of the country when Rosenthal called.

Foxman says Buchanan is "obsessed" with "baiting Jews. ... Over the last 10 years he has worn the hat of Holocaust revisionist, defender of convicted Nazi war criminals and Israel-basher."

But Buchanan says his criticism of Israel is of recent vintage. "From 1967 to 1985, I was an uncritical apologist for Israel," he says. "I was a {Menachem} Begin man all the way. I believed they should have annexed the West Bank and Gaza." But he says a series of events, including the Palestinian uprising, has "soured" him on Israel and that he now believes the Palestinians should be given their own state.

As for denigrating Congress as "Israeli-occupied," Buchanan says matter-of-factly that the American Israel Public Affairs Committee "has enormous power on the Hill. Why not recognize it and say it? Everyone knows it."

The Columnist's Other Side

For all his political bomb-throwing, friends say the private Buchanan is far different than his public image. Buchanan likes to jog, read and spend time with his wife and business manager, Shelley, a former assistant to Rose Mary Woods in the Nixon White House. The couple, who have no children, live in a million-dollar house in McLean.

"Pat is the sweetest human being on a one-to-one level that you'd ever meet, an incredibly gentle, warm, sweet man," says Mona Charen, a moment after noting that one of his columns on Auschwitz "sent a cold chill down my spine."

When Buchanan was promoting his 1988 autobiography, an associate recalls, he could not believe that a Washington columnist he had never met refused to have lunch with him because the man found Buchanan's rhetoric offensive. "Pat was genuinely stunned that someone would not like him because of something he wrote," this person says. "To Pat it's all business. He doesn't understand he can provoke real feelings of enmity and hatred and rancor."

If Buchanan's ideology seems a curious mix of Roman Catholic fervor and street-corner aggression, it may be because his Irish father taught him to box in the basement of their Chevy Chase, D.C., home while cloistered nuns drilled him with lessons for eight years at Blessed Sacrament School. Buchanan's father, an authoritarian who periodically beat him with a belt, also passed on his admiration for Joe McCarthy.

One of the best-known graduates of Gonzaga High School, Buchanan also worked part time at Burning Tree Club, where he once caddied for then-Vice President Nixon (they relieved themselves together in the bushes).

Upon graduating from Georgetown in 1961 (he was reinstated after the assault incident) and Columbia Journalism School (where his credits included "sucker-punching" a fellow student in front of the dean), Buchanan interviewed for a job at The Washington Post. But he got "sidetracked into a foolish argument with the Post editor over their biased coverage of everybody from Joe McCarthy to Richard Nixon," he writes in his book, "Right From the Beginning."

Buchanan found his conservative voice as an editorial writer for the St. Louis Globe-Democrat. Among other things, he penned attacks on Martin Luther King Jr. with unsigned material handed him by the publisher that Buchanan believed was supplied by the FBI.

Buchanan, who first signed on as a Nixon aide in 1965, made his presence felt as a White House assistant by scripting Vice President Agnew's harsh attack on the liberal media as "a small and unelected elite." ("One of the great sustained polemics of the 20th century," Buchanan says modestly.)

After defending Nixon to the bitter end during Watergate, Buchanan established himself as a columnist and radio and television commentator. He frequently drew attention on sensitive subjects such as AIDS, which the columnist described as "nature ... exacting an awful retribution" on "the poor homosexuals."

Buchanan's ability to infuriate opponents reached new heights when he joined the Reagan White House in 1985. In an opinion piece in The Washington Post, he said that with a vote on aid to the Nicaraguan contras, "the Democratic Party will reveal whether it stands with Ronald Reagan and the resistance -- or with Daniel Ortega and the communists."

Buchanan considered running for the presidency in 1988, but decided it would split the conservative movement. Since communism began collapsing around the globe, he has surprised friends on the right by staking out an America First-style foreign policy that skeptics deride as isolationism.

But it is Buchanan's repeated and inflammatory comments on subjects involving religion that drives his detractors wild:

He called a Supreme Court ruling banning prayer in public schools the beginning of "the systematic de-Christianization of America."

Criticizing the New York Times for playing down a homosexual protest at St. Patrick's Cathedral, he questioned whether the paper would have done the same "had a synagogue been so desecrated."

Assailing an article by Jewish scholar Leon Wieseltier that criticized establishment of a convent at the Auschwitz death camp, Buchanan wrote that "anti-Catholicism is the antisemitism of the intellectual. Let's hope the nuns at Auschwitz are praying for him; he needs it."

"A hater's rhetoric," responds Wieseltier, the literary editor of the New Republic. He adds: "There's no question there can be in a religious Catholic a theological basis for antisemitic emotion, though I emphasize that not all religious Catholics are antisemites. The roots of some of this man's feelings about the Jews may be theological."

Despite the searing nature of such attacks, Pat Buchanan remains a member in good standing of the Washington establishment, part of which has rallied to his defense. Conservative columnist Robert Novak, a longtime friend and chat-show colleague, says he is convinced Buchanan is no antisemite.

"I thought Mr. Rosenthal's column was outrageous," Novak says. "For a former editor of the New York Times and distinguished journalist to equate Buchanan's views with Auschwitz is in the category of McCarthyism. ...

"I wouldn't use the kind of rhetoric Pat does," Novak says. "That's his style. If he was more careful, he wouldn't be in this difficulty, but he wouldn't be Pat Buchanan."