The chances of New York Gov. Mario M. Cuomo's (D) making an impression at the Italian-American Foundation dinner were between slight and nonexistent.

He had been scheduled to speak at 9:30 p.m. It was 11 in the crowded Washington Hilton ballroom before he got to his feet. The dinner, an annual affair, combines some of the more trying features of the political convention and the Academy Awards ceremonies, in that every politician has to be presented, and those who receive anything have lists of thank-yous that begin with Mama and seem sometimes to go back to Dante and Beatrice.

The Italians habitually read the roll of all their members of Congress. They are unlike the Irish, who came here 60 years earlier, and who, finally, with the election of one of their own to the presidency, achieved an ethnic ease, which allows shorter speeches and longer jokes at their tribal rites. But the Italians are still waiting for the ultimate ethnic honor, and their rhetoric tends to be as long-winded as it is defensive. There are no givens, assimilation is a sometime thing.

Each notable had to be introduced by a separate introducer -- all the leaders of the foundation required their moment in the sun -- who had to be introduced by master of ceremonies Jack Valenti, who is not himself a laconic man. The person who introduced Alan Alda, one of three recipients of a lifetime foundation award, gave a resume that took the world famous and adored Hawkeye through a yearly review of his life, with each screen director's prize and writer's award carefully annotated, as if no one in the room would accept him without a definitive history of the honors conferred on him by other people.

Alda gave a bravura performance. He shared his award with his wife, proclaimed -- and demonstrated -- his joy in being "a life-loving Italian" and sat down leaving the room wondering how in the world Cuomo could follow his act.

It was not just the lateness of the hour that was against him. Italians are notoriously Republican. They are deeply conservative: In 1984, Geraldine Ferraro, the first Italian American chosen for a national ticket, was booed at the banquet. It was partly cultural, an Italian American explained, they "weren't sure about the first being a woman, and then it was her husband."

The idea of Cuomo, an unabashed liberal, who stunned the country with one speech six years ago, becoming the Democratic nominee has Italians both prideful and nervous. They fear that if he is nominated, the Roger Ailes of the day will be dispatched to Sicily to dig up Mafia dirt, or to New York City to record its deterioration during the Cuomo years.

But he was seemingly above politics in confronting the constituency that should be his base if he decides to go. He made a crack about the tedium -- "we are in danger of making this a year-long dinner" -- made the obligatory comparisons of the evening's stars to Caesar and Garibaldi. He spoke of Italians as a people born knowing things others never learn.

He switched abruptly to the New World and the trials of the immigrant, of his father, a ditch-digger, 5 feet 6 1/2 inches tall, who never went to the track or the movies or a picnic. He was too busy earning money so his children could have the education he never got.

He told tales they all could have told of ethnic slights and "snide condescension." He was first in his law school class at Fordham, but could not get a single interview on Wall Street. The dean suggested a name change.

"Can you imagine me with white shoes, bouncing up with a tennis racquet saying 'read my hips,' I went to Yale. I'm Mark Conrad."

They howled.

He told of a poll taken early in his political career, when "6 percent knew my name, and 9 percent had a suspicion of Mafia connections."

But his message was not self-pity. He told them that they had to do better: "We should make this world a wider world, a wiser world, a sweeter world."

There was a pause in the mesmerized ballroom, then a roll of applause.

"Wouldn't it be a shame if we, having heard those cruel epithets of 'wop' and 'guinea' and 'dago,' were to sit back now and talk about the 'spics and the niggers'? What a shame it would be if we who were victims of racism and stupidity should project it ourselves now that we have become secure."

It was a compelling, unexpected call to conscience. They rushed up to shake his hand. A gallery formed on either side of him to see him off.

He left behind consternation and admiration. "A presidential speech," breathed a reporter from Trieste. "The greatest president we could ever have," said a woman from New York. A midwesterner shook his head. "He is magnificent, but it can never be -- because of the things he said up there -- the prejudice."