In the FBI's dossier he is listed as Irving David Rubin, 56, a self-described conservative Republican, Air Force veteran, married for 21 years and the father of two children.
To everyone else he is Irv Rubin, chairman of the Jewish Defense League, an acute embarrassment to most mainstream Jewish organizations, whose "contemptible activities," in the words of the Anti-Defamation League, have cumulated in "a long track record of intimidation and bullying tactics."
By his own count, Rubin has been arrested 40 times, and he and his associate, Earl Krugel, are now sitting in a federal detention center in downtown Los Angeles. They are charged with conspiracy to blow up a mosque, the building housing a Muslim organization and the offices of a congressman of Lebanese descent.
The roots of Rubin's aggressive stance and militant outlook can perhaps be traced to his Montreal childhood, where, he says, his mother told him to get out and fight a kid who had called him a dirty Jew.
At age 16, he and his family moved to the San Fernando Valley, and five years later, he enlisted in the U.S. Air Force. Discharged, he proudly served as a page at the 1964 Republican Convention in San Francisco, which nominated Sen. Barry Goldwater as its presidential standard bearer.
Rubin's life took another turn -- permanently -- when he heard a speech by Rabbi Meir Kahane in 1971 and was enthralled when the rabbi declared, "Don't sit down and have a cup of coffee with a Nazi. Don't try to be a nice guy. Smash him."
Kahane also perceived the United States as the likely site of a future Holocaust.
The tall, husky Rubin loved the message. He joined Kahane's Jewish Defense League and soon participated in protests on behalf of Soviet Jews, duked it out with neo-Nazis and, just as quickly, was arrested on an attempted murder charge in the case of a Nazi he had confronted in a Hollywood television studio.
In 1978, he got his first national exposure at a news conference protesting a neo-Nazi march in Skokie, Ill. In a typically flamboyant gesture, Rubin held up five $100 bills as the proffered reward to anyone who maimed or killed a Nazi party member.
With a keen ear for the effective soundbite, Rubin offered to raise the reward to $1,000 "if they bring us [a Nazi's] ears. This is not said in jest, we are deadly serious."
Kahane, Rubin's role model, resigned as head of the JDL in 1974, after moving to Israel, where he formed the Kach Party. He was elected to the Knesset in 1984 on a platform that included the incendiary plan of transferring or expelling all Arabs from Israel.
Kahane was designated a racist by Israeli authorities and forbidden to run in the 1988 elections. In November, 1990, Kahane was assassinated in New York by Egyptian-born extremist El Sayyid Nosair.
(In an odd twist, a 1998 Associated Press report has surfaced, linking tapes and books on military techniques found in Nosair's apartment to Osama bin Laden's terrorist network. The AP story noted that "the killing of Kahane was at first viewed as an isolated attack, but now is seen as the kickoff of a U.S. terrorism campaign by militant Islamic fundamentalists.")
The slain rabbi's son, Binyamin Ze'ev Kahane, took over leadership of the Kach Party and formed another organization, Kahane Chai.
Both organizations were labeled "terrorist" by the Israeli government and outlawed. The younger Kahane and his wife were killed Dec. 31, 2000, in a West Bank ambush.
Back in the United States, Rubin stepped into the JDL power vacuum and became its "national chairman" in 1985. The title was a bit grandiose, because the JDL, with modest membership in the best of times, had split into two groups.
The New York wing, renamed the Jewish Defense Organization, was led by Mordechai Levy. Rubin and Levy have become bitter enemies, exchanging accusations and subpoenas over the years.
In 1989, Levy was convicted of firing an AR-25 aimed at Rubin in Manhattan.
Currently, Rubin goes by the title "chairman" of the JDL. In his first year as JDL leader, the organization came under investigation in the Oct. 11, 1985, murder of Alex Odeh, an Arab American activist killed in a bomb blast at his Santa Ana office.
Rubin denied responsibility but said that Odeh "got exactly what he deserved." The JDL leader has since said repeatedly that he regretted making the statement, because it alienated would-be supporters and lessened his credibility.
When Rubin's arrest was initially announced last week without the charges being specified, there was widespread speculation that it was connected with the Odeh case. The belief was shared by Sammy Odeh, the victim's brother, who told The Journal that the killers of his brother would finally be brought to justice.
Over the past decades, the JDL has struck out against perceived softness in the Israeli government and American Jewish organizations, as much as against Nazis and other anti-Semites.
For instance, the JDL Web site marked the assassination of Prime Minister Yitzhak Rabin by a Jewish extremist by stating, "We feel Yigal Amir wasted his precious life. Taking the life of Rabin was not worth Amir spending the rest of his life in an Israeli prison ... The Israeli people would have taken Rabin out of office."
In the same vein, the JDL hailed Dr. Baruch Goldstein, who killed 29 Arabs praying in a Hebron mosque in 1994, as one of its charter members.
One of the closest observers of Kahane and Rubin has been the ADL, which compiled a report of 21 densely packed pages listing the JDL's violent acts in Israel and the United States between 1969 and 1995. Rubin, in return, has frequently attacked the ADL in JDL leaflets and at public meetings.
Whether it's middle age or a change in tactics, in the last few years, Rubin seems to have become less publicly aggressive and has appeared in three-piece suits at public forums hosted by such institutions as the liberal University Synagogue.
One who got to know both Kahane and Rubin in the 1960s and '70s was Si Frumkin. All three were involved in protests and demonstrations on behalf of Soviet Jews.
"You can approach a problem with a rapier or a club," Frumkin observed. The National Council for Soviet Jews "used the rapier; JDL used a club. I can't say which method was more effective."
Comparing the two JDL leaders, Frumkin said that Kahane "was a PR genius. Rubin had the same fire in the belly as Kahane but is not as charismatic,"
With the name recognition created by Kahane, "the JDL should have become a well-known, large and well-financed organization, but now it seems to have trouble even attracting young people," Frumkin said.
Although the charges currently leveled at Rubin and Krugel can carry a 35-year prison sentence, few knowledgeable lawyers expect their conviction.
While the JDL has been investigated on murder and attempted murder charges a number of times, Rubin has never been convicted of a felony.
"He [Rubin] has the uncanny ability to come right to the line and he doesn't cross it." Roger J. Diamond, one of Rubin's previous lawyers, told The New York Times, "If he didn't come close, he wouldn't have been charged."
The latest posting on the JDL Web site calls the current charges an "obvious act of governmental appeasement of the Muslim community. Please rest assured that Irv and Earl will be cleared of any wrongdoing when they have their day in court."