It's no secret that Senate Majority Leader Howard Baker (R-Tenn.) would love to have Ronald Reagan's job. But with the president sitting at Baker's elbow, no one dared talk seriously about that last night.

True to their high-financed reputation, the Republicans raised close to $1 million at a $1,000-a-head dinner honoring the retiring Baker. The money will go to Baker's political action committee and will be funneled to the 17 Republican senators up for reelection next year. Ironically, Baker won't be needing any money himself this time. Unless he runs for president. (More on that later.)

An exceptionally high-order line-up of Republicans--President Reagan, Henry Kissinger, most of the Cabinet and just about any GOP name familiar from the 7 o'clock news--jammed into the Hyatt Regency last night to say an early goodbye to Baker after his 18 years in the Senate.

Reagan, in remarks praising Baker, said, "Since 1966, Howard Baker has made the picture as well as taken pictures . . . You will be missed and if you make yourself scarce, we'll come looking for you."

Conspicuously absent was Interior Secretary James Watt, who has been under fire by members of his own party in the last week for describing an advisory committee as "a black . . . a woman, two Jews and a cripple."

"If I were the president, he'd be gone by now," said Sen. William Cohen (R-Maine). "In terms of credibility on the Hill, he doesn't serve the president well."

"If I were the president I'd send him off to study the coal fields in Germany for a while until things cooled down," said Sen. Ted Stevens (R-Alaska).

Sen. Robert Dole (R-Kan.), who has been the GOP senator most vociferously crusading for Watt's removal, said last night that he did not know how it would turn out.

"I know there's still polling going on," he said. "Is he here?"

Baker's spokesman, Tom Griscomb, said that he was told all of Watt's appearances have been canceled.

"Am I in the wrong uniform?" fretted Kissinger, in black tie and one of the first to arrive.

"You're never in the wrong uniform," consoled Baker in blue suit. The two men were whisked off to a Very Private and Expensive reception for the big donors.

In the aggressive world of political fund-raising, conventional wisdom says that it helps to have the White House rooting for you. Which is why in an election period threatening to send the Senate back to the Democrats, Reagan and the Republican showcase are more than happy to lend an hour or two.

For those who gave $5,000 or raised $10,000, a handshake from Reagan, Kissinger and Baker, as well as some shrimp snacks, were available before the dinner. This lasted all of 17 minutes.

Kissinger was in fine form at the dinner.

"I never dreamt that one day I would serve in such a capacity," he said. "A Republican majority in the Senate is difficult to fathom . . . added to the problem of how I would get here from Krypton."

Other Kissingerisms:

White House chief of staff James Baker and national security adviser William Clark were walking down the corridor together. "I'm right behind you," said Baker. "That's the most frightening thing that's happened to me all week," said Clark.

"It is a great privilege for me to be here not only with the president . . . but all of his successors are here, too."

"Just because Howard Baker is up here doesn't mean he is any closer to the White House than all of you. It is true he has his own one percent plan. But it is the same one percent plan he adhered to so faithfully in the 1980 election."

Baker's unexpected plans for retirement have once again raised the question of whether he will run for president. A presidential candidate in 1980, Baker is certain to run again should Ronald Reagan decide against it.

"This PAC cannot be turned into a presidential committee," said Griscomb when asked whether Baker could dip into the fund should he run for president.

But, that being said, there is no law prohibiting Baker from calling in his chits for Senate support should he run.

At night's end, Baker seemed wistful.

"I'd like to do something else," he said. "Experience a different perspective."