One of the subtler pleasures of winning is that you get to praise your opponents and they have to accept it graciously. Last night, the new Senate majority leader, Bob Dole, reveled in the experience, praising people right and left at a Republican leadership dinner at the Library of Congress. With President Reagan, Vice President Bush, much of the Cabinet and the Republican majority of the Senate listening, Dole lauded his four opponents in the leadership race.

"Any of them would have made an outstanding majority leader," he said. "Seeing your name beside theirs on the candidates' roster is apt to go to your head. Of course, I can count on everyone here to bring me back to earth about 10 times a day each for the next two years."

The talk was mostly of pride in the Senate and the hard fights ahead, with Reagan emphasizing the need to reform the tax structure and "get the budget monster back in its cage." But as could have been expected of a program that included both Dole (who is called a "wit" at least as often as he is called a Kansan) and Reagan (no enemy of the chuckle-inducing anecdote), jokes were also in.

"Friends in the other party are saying a 49-state sweep was not a mandate," Reagan said, "and that I personally am a lame duck. Well, I'm so lame, I decided to get a cast and that will be useful when I have to do some kicking."

He paused for a second, smiled at Bush and, referring to a comment Bush made following his debate against Geraldine Ferraro, added, "I won't finish that phrase. It's an old athletic saying."

Of course, humor is not everyone's forte. Sen. Jesse Helms, who promised his constituents he would not trade the chairmanship of the Agriculture Committee for that of the Foreign Relations Committee despite conservative pressure to switch, didn't smile as he lit a cigarette and explained his plans.

"Mr. Lugar succeeds Sen. Percy," he said, "and I'll stay with Agriculture, just as I have said a dozen times publically. No one believed me. I figure we made a commitment, and age 63 is a bad time to start breaking them."

But in general, pointed humor suddenly seemed to be a prerequisite for leadership.

"They'll bring color and flash and humor and quotability," said Sen. John Danforth (Mo.) of Dole, whom he nominated, and new majority whip Alan K. Simpson (Wyo.), "and that will be very helpful to us. They're the two funniest people in the Senate.

"I think it's very important for our party in the Senate. Also, it facilitates business. It is easier to do business if you can use humor as a tool and those guys both can."

The color and flash began earlier in the day soon after Dole's victory. Balloons, letters, phone calls, flowers -- that's all pretty predictable. But how many newly named Senate majority leaders get a congratulatory schnauzer?

"It was my idea for Christmas," said Transportation Secretary Elizabeth Dole of the miniature schnauzer, bedecked in red ribbon, that was sitting calmly on a chair in Bob Dole's office earlier in the day. "It got moved up a bit."

The Doles are very good at this kind of thing. Bob made sure to sprinkle his afternoon press conference with jokes. Elizabeth somehow managed to have the gray and black schnauzer coordinate with her gray and white suit. And even though receptionists and press secretaries kept claiming all was chaos, the streamers were neatly hung and the balloons carefully clustered long before anyone had time to celebrate.

But then, what's a well-trained staff for?

"It's a nut house," said Dole press secretary Walter Riker just before the press conference. "Everyone and every show in the world wants him."

An aide peered around a partition. MacNeil/Lehrer at 4:30? A phone rang, a tape started to spin automatically, and some reporter from Kansas was hearing a recording of an interview Riker had taped with Dole as soon as the final votes were in. Another phone rang.

"It's just a nut house," Riker told the caller.

Then the nut house relocated to the Finance Committee hearing room, where Dole received his dog.

"This is my new dog named Leader," he said. "It's an indication of where my leadership is going."

The first question was inevitable.

The answer: "House-broken, but not Senate-broken."

Back in the office, a receptionist calmly answered the constantly ringing phones, confirmed the news, received the congratulations and told a supporter that yes, she had his message that it was the best thing to happen since we won WWII, while a delivery man carried in bowl after bowl of flowers and pot after pot of standing plants and an ABC camera crew filmed every leaf and blossom. The crew loved it when four six-packs of beer arrived, a present from Sen. James McClure (R-Idaho), who was eliminated first in the race for majority leader.

A high point came at 3:46, when the first piece of mail addressed to the Majority Leader arrived. Cheers rose from the staff.

A weary-faced family of tourists, the Bigongiarises from Kansas, walked in, Dr. Bigongiaris saying something about getting tickets to see the Senate as his 6-year-old son Jeffrey stared at the balloons.

"It must be someone's birthday," Jeffrey said, in the voice of a small child who wishes it was his.

As Bob Dole, who had been asked during the conference if he would be able to continue to help Kansas' constituents from his new position, returned to the office, he stopped to shake each and every Kansas hand.

"It's a pretty exciting day around here," he said. "We're not sure we understand it all yet."

Jeffrey and his 9-year-old brother Tony obviously didn't understand it all either. They just smiled.