The mighty and the monied came together with President Reagan among the monuments last night at the Washington Convention Center for what was described as the Republican Party's most successful fundraiser ever.

Painted wooden facades of the White House, the Capitol and the Jefferson and Lincoln Memorials -- each with its own head table -- decorated the walls, and a large replica of the Washington Monument stood smack in the middle of the room.

The $1,500-a-plate event raised nearly $7 million, to be split between the National Republican Congressional Committee and the National Republican Senatorial Committee, which was more than enough to keep spirits high. But the speakers, Reagan included, concentrated on hammering home the ongoing Republican mission. And the Democrats took a strong verbal beating.

Standing in front of an elaborate wooden replica of the Capitol, Reagan took the offensive. "If anyone has any doubts about where the other side still stands," he said, "all they have to do is look at the budget recently produced by the Democratic House of Representatives. It's a budget only Tip O'Neill's mother could love."

Moving on to the tax reform bill now before the Senate, Reagan admitted he had had some doubts as it "wended its way through the passages of Congress." To illustrate those doubts, he recounted a joke about Marilyn Monroe meeting Albert Einstein and suggesting that the two get married. Einstein, the president said, responded, "What if the kids get my looks and your brains?"

"But thanks to the farsighted, imaginative leadership of Bob Packwood and the other members of the Senate Finance Committee," he went on, "we can all be proud parents."

The president seemed impressed at the amount of money that had been raised. "Gosh, Boone," he said to oil tycoon T. Boone Pickens Jr., who will chair next year's fundraiser, "Seven million dollars this year. About enough to buy a small oil company."

Other speakers ranged into different territory. Illinois Rep. Guy Vander Jagt expressed tongue-in-cheek concern about what Ronald and Nancy Reagan will do after their time in the White House. He offered a suggestion: "There are 27 Democratic Congressmen in California. Pick one [seat] out and the NRCC will provide full funding."

Other speakers, in addition to dinner chairman Drew Lewis, included Vice President George Bush, who sat with his wife Barbara in front of the Lincoln Memorial; Senate Majority Leader Bob Dole of Kansas, who manned the Jefferson Memorial station; and House Minority Leader Bob Michel of Illinois, who seemed pleased to be sitting in front of the White House.

The vice president was introduced by Pennsylvania Sen. John Heinz, who was looking beyond the 1986 congressional elections. Joking that Bush has associated successfully with actors, he said that in 1988, he "wouldn't be surprised if there were a Bush-Eastwood ticket," a reference to actor Clint Eastwood's recent election as mayor of Carmel, Calif.

Bush opened by praising Nancy Reagan for her work in fighting drug abuse, and the crowd of 4,000 responded with a standing ovation for the first lady. He then added fuel to the partisan fire, saying that the American people "agree with our policies. They don't like the policies of the Democratic Party."

Michel bantered awhile with Dole, but admitted he had trouble seeing the senator clearly over the large Washington Monument at the center of the enormous room. "Bob Dole," he said, "has the wittiest mind in Washington and has the majority in the U.S. Senate. I'll settle for the minority [in the House] and remain my dull old self."

Thus introduced, the Kansas senator seemed to invoke the faithful to win yet another one for the Gipper. "The one way to reward Ronald Reagan for all of his good work," he said, "is to keep the United States Senate Republican."

Scattered among the 400 pink-and-green tables were Secretary of State George Shultz, Treasury Secretary James Baker, Commerce Secretary Malcolm Baldrige, CIA Director William Casey, Attorney General Ed Meese, about 45 senators and 140 congressmen.

Bathed in candlelight, guests dined on filet mignon, salmon mousse and chocolate ice cream bombe and danced to the tunes of the Gene Donati band.

After the speeches, Lewis accepted a special award for his services to the party. He bestowed thanks all around and turned the floor over to Michel, who with the help of the band led everyone through a chorus of "God Bless America."