Battered by aggressive investigators and weakened by incompetent leadership, most of America's traditional Mafia families appear to be fading out of existence, law-enforcement officials and independent experts say.
The Mafia remains potent in the New York City area, where officials say it is hard to uproot because it has five separate and large crime families, and in the suburbs of Chicago.
But in most other areas, where prosecutors have to contend with only a single family, the legendary mob that once controlled whole labor unions, city governments and criminal enterprises has clearly lost its grip.
Officials say the convictions of top Mafia leaders and their hierarchies have dismantled thriving underworld organizations in Philadelphia, New Jersey, New England, New Orleans, Kansas City, Detroit, Milwaukee and St. Louis.
In Los Angeles, investigators speak of the "Mickey Mouse Mafia," saying the mob is so enfeebled that illegal bookmakers refuse to pay it for the right to operate.
In Cleveland and Denver, where Mafia gangs once flourished, officials of the FBI say each city is left with a lone mobster who was "made," or formally inducted in a secret ritual.
Many experts and officials say it is premature to write the Mafia's obituary, and they emphasize that its decline does not mean that organized crime has been banished: Other groups are moving in to take the Mafia's place.
But experts say the recent defeats of the Mafia will nevertheless mean real gains for the public, reducing the financial and social costs of rigged public contracts, of domination of labor unions like the Teamsters and Longshoremen, and of influence in the construction, trucking, trash-collection and garment-manufacturing industries.
While there is wide agreement that the Mafia is declining, there is much disagreement on the causes.
Law-enforcement officials generally credit a long-term strategy adopted by the Justice Department and the FBI in the early 1980s: developing cases against the top leaders of organized-crime families and relying largely on the Racketeer Influenced and Corrupt Organizations Act, or RICO, as a courtroom tool.
By concentrating on enterprises rather than individuals, federal prosecutors in the past five years have removed the high commands of families through the convictions and long prison sentences of almost 100 top Cosa Nostra leaders.
The chief architect of the RICO act, G. Robert Blakey, a professor of law at the University of Notre Dame, admits he was surprised by its impact.
"It was sort of like George Kennan's containment policy of the bTC Soviet Union," he says. "We tried it and, by God, it worked."
But two other experts, Peter A. Lupsha and Howard Abadinsky, say demographic changes, too, have helped undermine the Mafia.
Lupsha, a political scientist at the University of New Mexico who is a consultant on organized-crime matters for federal and state agencies, and Abadinsky, founder of the International Association for the Study of Organized Crime, a research organization, cite these factors:
* The dispersal of white populations away from urban neighborhoods. This diminished both the Mafia's political influence and the surreptitious protection that organized-crime bosses often got from the local police and political machines.
* A new generation of Mafia leaders who took control after the convictions or deaths of previous bosses and capos, or captains, but were less competent than their predecessors.
* The disintegration of traditional Mafia loyalties, with members breaking the code of silence to become informers against leaders.
* The emergence of rival crime groups -- including Asians, Jamaicans and Colombians -- who dominate drug trafficking and illegal gambling, especially in the inner cities.
Many experts say the American Mafia lacks the nerve and ability to compete violently with the new underworld rivals.
"The new drug gangs are wild groups, and the old-timers don't want any confrontations with them," says Ralph F. Salerno, a former New York detective who is a consultant to congressional committees on organized-crime matters.
The largest Mafia concentration, 1,200 of about 2,000 "made" members nationwide, is in New York City, Long Island, the suburbs north of the city and in Northern New Jersey. With five families, New York is the only area where so many factions have co-existed for half a century.
Law-enforcement officials maintain that the campaign to eradicate the Cosa Nostra in New York is hampered by the mob's large numbers, its extensive illicit networks and an ample supply of recruits to replace convicted capos and soldiers.
Since 1985, however, the bosses and underbosses of the five families -- Gambino, Genovese, Lucchese, Bonanno and Colombo -- have been slain or sentenced to long prison terms. The changing of the guards within such a short period has created feuds, sapping the strength of every family.