It was one of those nights when the crowd was startled by its own breadth and enthusiasm, when everyone was "a beautiful human being," when yesterday's and tomorrow's battles faded in the face of history and humor.

"Sure, I've said some things about Tip, and Tip has said some things about me," President Reagan told more than 2,000 guests at last night's party in honor of retiring House Speaker Thomas P. (Tip) O'Neill, "but that's history, and anyway, you know how it is -- I forget."

You know how it is -- the audience of black tuxedos and emerald green ties in honor of St. Patrick's Day laughed and laughed.

Reagan and O'Neill have done more than say "some things" about each other in five years of political wrangling, but each speaker, from Gerald Ford to Bob Hope to Sen. Edward Kennedy (D-Mass.), was determined to be more bipartisan than the last.

"I have traveled the nations of the world," O'Neill said in thanks to Reagan for making his brief appearance before the main course. "You see on one side of the hall the leadership and on the other side the minority and they don't talk. We have different philosophies, but I want to tell you how much I admire you . . . Your charm, your humor, your wit -- Sometimes when I get up in the morning I tell myself, 'Don't let it get you, old boy.' "

The presidential wit was much in evidence: "To be honest, I've always known Tip was behind me -- even if it was only at the State of the Union," Reagan said. "At each proposal I made, I could hear Tip whispering to George Bush, 'Forget it!' "

There were presents for Tip, as everyone but Hope called him throughout the night ("Mr. T" was the comedian's nickname for the speaker): Irish citizenship for both O'Neill and his wife Millie from Irish Prime Minister Garret FitzGerald; a road sign from Ireland pointing the way to O'Neill's family home in Donegal, present from Kennedy; an American Express platinum card for "two years from now when you're going around the country saying, 'Do you know me?' " from Ford.

Irish tenors entertained and Irish whiskey quenched the thirst of the guests at the Washington Hilton, who had paid $1,000 each to honor O'Neill and help his alma mater, Boston College. For that price, they also got two Irish crystal glasses each; several of the more enterprising were seen leaving with three or four boxes of crystal under their arms.

And this event is only the beginning. After all, the man has another nine months in office before he'll need that platinum card.

"I want to welcome you," Kennedy told the crowd, "to the latest in the 1986 weekly series of Tip O'Neill retirement parties."

In addition to their shared Irish heritage, Kennedy and O'Neill have other things in common. O'Neill succeeded John Kennedy in his congressional seat, and Robert Kennedy's son Joe is now running for the soon-to-be-vacated seat.

"I want to thank Tip O'Neill for spending the last 34 years keeping the seat warm for my nephew Joe," Kennedy said. Much to his amusement, O'Neill later realized he had the same joke, almost word for word, in his speech. "I wonder who's writing your stuff, Ted," he laughed.

"I owe Tip a lot," Kennedy said in his remarks. "For one thing, he lent me his diet."

Yes, it can be said. The speaker is a sizable figure.

Bob Hope's first girth joke: "He's a big man in lots of ways. House speaker, party leader and fifth stop on the Gray Line tour of the city."

Bob Hope's second girth joke: "Tip has announced he's retiring -- he's going to ride off into the sunset. That should be a hell of a collision."

Bob Hope's third girth joke: "It's fun to play golf with Jerry and Tip. At least when Ford's hitting, you've got something substantial to hide behind."

Entering the non-VIP reception, where a mere 2,000 or so attempted to mill but ended up just standing still, Rep. Patricia Schroeder (D-Colo.) said the evening was a celebration of "American politics -- what else?"

The catering service seemed to understand this, allowing for a long pause between the fish course and the entree so everyone could spend some more time clustering and talking and looking alternately riotously happy and very serious. The talkers included such people as Sen. Paul Laxalt (R-Nev.); Senate Majority Leader Robert Dole and his wife, Transportation Secretary Elizabeth Dole; actress Cicely Tyson, who sported green-frosted hair; and numerous Bostonians.

Or, as one guest said, "7,000 of his closest friends."

"It's so bizarre," said Sen. John Kerry (D-Mass.), looking around at the heavily Irish, heavily New England crowd. "Seeing half the people here, you say, 'Now what congressional district in Massachusetts are they from?' "

Joe Kennedy was in attendance, as were his mother Ethel, brother Michael and aunt Eunice Shriver.

"Good-ta-see-ya-how-ya-been?" candidate Kennedy was working his way through the lobby before the dinner. "Sure," he said, this was all part of campaigning, but added, "It's really more than that. It's Tip O'Neill's night and it just seemed appropriate to come down and pay respect to somebody who's done so much for the people of the state of Massachusetts" -- and here his constant smile grew even wider -- "particularly for the people of the Eighth Congressional District!"

*"If you're going to try to fill those very big shoes, you have to have some respect for the man, of which I have a very big amount."

Rep. Tony Coelho (D-Calif.) said of O'Neill, "He is a Democratic presidential figure, in effect. He is our leader and everyone across the country knows him and he will be a great loss. There's a presence about him. He's noticed wherever he goes. He fills a room. There aren't many political figures who do that. The president of the United States does that, whoever the president is. Not many speakers have."

Testimonials are as common in Washington as presidential hopefuls, and usually as partisan, but at this one the dinner committee ranged from Democratic National Committee head Paul Kirk and AFL-CIO head Lane Kirkland to former White House deputy chief of staff Michael Deaver. Both Ford and Jimmy Carter performed that vague function of serving as "chairmen." Carter had a previous engagement, but Ford was there. He spoke of a serious yet friendly discussion between congressman and vice president about the future of the country that took place shortly before Richard Nixon resigned.

" 'Christ, Gerry,' " Ford remembered O'Neill as saying. " 'Isn't this a wonderful country? We can sit here now and talk like this, and 18 months from now I'll be going around the country kicking your ass in.' "

Perhaps because it was St. Patrick's Day, sentiment flowed. The dinner raised more than $2 million for Boston College, the charity O'Neill chose for the event. On each seat lay a photo album chronicling O'Neill's life that opened with a note signed simply, "Millie."

And O'Neill, in remarks that started with expressions of gratitude and memories of past golf games and ended in a declaration of love for America, "the fairest, the freest and the most progressive society in the world," as he called it, was the most sentimental of all.

"Millie and I went around in high school," O'Neill said of his wife in his remarks. "She's been a mother and a father to the family when I was down here in Washington . . . Mother, if it's possible to love you more, I love you more and I want to thank you for 45 years."

She got a standing ovation.