On the eve of the first real test of his reelection campaign, Jimmy Carter gave an elegant dinner party where a string quartet played. Then he went out to the theater.

New Hampshire, it appeared, was something all those other candidates could fight over.

But he confessed to a little anxiety when it came to the after-dinner toast.

"It's been difficult for me to keep my mind" he began, cut off by laughs from 38 governors and their spouses, resting between tossed salad and dessert in the White House East Room. "As Governor Byrne [Brendan Bryne of New Jersey] said," Carter then continued, "he wouldn't relax until he knows who wins. As you know, Penn and Princeton are playing for the Ivy League championship."

The president looked tired and drawn at a dinner where "Have you heard anything from New Hampshire yet?" was question A.

Nobody had, at least by the time Carter and the governors headed over to the Kennedy Center for a performance of "The Elephant Man." But aides to Carter were seen skulking around the White House phones and Gene Eidenberg, a deputy assistant to the president, admitted over his wine glass that he'd probably sneak into the White House ushers' office to make some calls north.

By intermission, White House staffers had the preliminary New Hampshire vote count written on 5x7-inch index cards and were showing them around to the crowd.

During dinner, Carter received election results on similar index cards, complete with projections by the three networks. He shared them with Rosalynn and guests at his table.

And during a Kennedy Center intermission buffet, where guests who hadn't eaten enough ice cream and petit-fours at the White House got baked brie and pastries, Carter noticed that Gov. Byrne had a radio. The president approached and asked how he was doing.

"You're 12 points ahead," Byrne said he told him.

The governors seemed to enjoy being in the thick of things, especially after their three-day conference here that Ed Herschler of Wyoming branded as only good for "getting away from a legislative session" back home.

"What were we talking about today?" continued Herschler. "Nothing. We didn't do a damn thing."

The conference was officially the annual winter meeting of the National Governors' Association, finished off and given a little glamor by the White House dinner. Everybody wore a tux or an evening dress, had broiled sliced pepper steak, and saw it as a nice opportunity to have some constructive chitchat with Carter.

"We can always sidle up to the president and say, 'How 'bout those coal roads that Secretary Goldschmidt says we can't have?'" said Richard Thornburgh, the Republican governor of Pennsylvania. "We'll be banging away."

Transportation Secretary Neil Goldschmidt did in fact appear, popping up in the Grand Foyer to crack a few jokes. There was no talk of coal roads from his end.

A few of the governors were discussing the early returns from New Hampshire. "My first thought," said Victor Atiyeh, the Republican from Oregon, "was that it would be Baker. Then I thought it would be between Baker and Bush, because that's where my politics tend to be. But my gut reaction was that it would be Regan."

And at least one guest -- Richmond Crinkley, producer of "The Elephant Man" -- was marveling at how unpreoccupied President Carter seemed about the results. "on a primary night, you would think the president's mind would be elsewhere," said Crinkley, who sat at the president's table. "But he gave a long and serious discussion about foreign policy. It was a masterful thing and revealed to me that he is a very serious-minded man."

Crinkley also was impressed by Carter's knowledgeable discussion of the book by Frederick Treves, which his play is based on: "There aren't 200 people in America who have read that book," said Crinkley.

But Carter also talked about his kids, according to Hattie Babbitt, who also talked about hers. She's the wife of Arizona Gov. Bruce Babbitt, and she sat next to the president at dinner. "Charming," she called him.

The White House people, predictably, talked victory. "I think everybody thinks he's going to do very well," said Mary Hoyt, press secretary to Rosalynn Carter."The question is -- how well?"

Philip Anglim, the lead actor in "Elephant Man," was one of the few at the White House dinner who didn't seem wholly absorbed by politics. "It's going to be very shaky tonight," he said. "We haven't had a rehearsal or anything."

"Oh really?" said Jane Hansen, a staff member to Jack Watson. "Well, drink a lot of wine."

When President Carter returned to the White House at 10:30 p.m., the network cameras and microphones waited like an army for his reaction to the New Hampshire primary. With his opera glasses in his hand, the president said he was "extremely pleased" about the projected margin from New Hampshire.

"This is a good demonstration of the support for what we are doing," said Carter, standing coatless at the diplomatic entrance of the White House. By his side was Rosalynn Carter, who had campaigned vigorously in New Hampshire. "I feel wonderful," she said. "I thank all the people we worked with." As the Carters started to move away from the press, the president was asked if Kennedy should withdraw from the race, "having lost in Iowa, Maine, and now New Hampshire." The president smiled but moved away quickly, saying, "You'll have to ask Senator Kennedy."

Guests at last night's White House dinner for the governors: Gov. Jay S. Hammond of Alaska (Guest: Laurie McGinley) Gov. & Mrs. Peter Coleman of American Samoa Gov. & Mrs. Bruce Babbitt of Arizona Gov. Bill Clinton of Arkansas (Guest: Ms. Carol Huber) Gov. & Mrs. Richard Lamm of Colorado Gov. Ella T. Grasso of Connecticut Gov. & Mrs. Robert Graham of Florida Gov. & Mrs. George Busbee of Georgia Gov. & Mrs. George Ariyoshi of Hawaii Gov. & Mrs. Otis Bowen of Indiana Gov. & Mrs. Robert Ray of Iowa Gov. & Mrs. John Carlin of Kansas Gov. & Mrs. John Brown of Kentucky Gov. & Mrs. Edward King of Massachusetts Gov. & Mrs. William Milliken of Michigan Gov. & Mrs. Albert quie of Minnesota Gov. & Mrs. William Winter of Mississippi Gov. Thomas L. Judge of Montana Gov. & Mrs. Charles Thone of Nebraska Gov. & Mrs. Robert List of Nevada Gov. & Mrs. Brenden Byrne of New Jersey Gov. & Mrs. Bruce King of New Mexico Gov. & Mrs. Arthur Link of North Dakota Gov. & Mrs. George Nigh of Oklahoma Gov. Victor Atiyeh of Oregon Gov. & Mrs. Richard Thornburgh of Pennsylvania Gov. & Mrs. Carlos Romero-Barcelo of Puerto Rico Gov. & Mrs. J. Joseph Garrany of Rhode Island Gov. & Mrs. Richard Riley of South Carolina Gov. & Mrs. Lamar Alexander of Tennessee Gov. & Mrs. Scott Matheson of Utah Gov. & Mrs. Richard Snelling of Vermont Gov. & Mrs. John Dalton of Virginia Gov. Juan F. Luis of the Virgin Islands (Guest: Julio Brady) Gov. Dixy Lee Ray of Washington (Guest: Marion Reid) Gov. & Mrs. John Rockefeller of West Virginia Gov. & Mrs. Lee Dreyfus of Wisconsin Gov. Ed Herscler of Wyoming Vice President & Mrs. Mondale Secretary of Agriculture Bob Bergland & Mrs. Bergland Mrs. F. Ray Marshall (Guest: Pat Lear) Secretary of Transportation Neil Goldschmidt & Mrs. Goldschmidt Secretary & Energy Charles Duncan & Mrs. Duncan Secretary of Education Shirley Hufstedler (Guest: Dr. Richard Gilman) Stuart E. Eizenstat, Assistant to the President for Domestic Affairs & Policy, and Mrs. Eizenstat Jack H. Watson, Jr. Assistant to the President for Intergovernmental Affairs (Guest: Marcia Thomas) Victor Marrero, Undersecretary of Housing & Urban Development (Guest: Suzanne McAllister) Victor Paimieri, Ambassador at Large & Coordinator for Refugee Affairs (Guest: Priscilla Clapp) Rear Adm. Roland G. Freeman, III, Administrator, General Services, Administration, & Mrs. Freeman Esther Peterson, Special Assistant to the President for Consumer Affairs (Guest: Lars Peterson) Robert T. Hall, Assistant Secretary of Commerce for Economic Development, & Mrs. Hall Eugene Eidenburg, Deputy Assistant to the President for Intergovernment Affairs, & Mrs. Eidenberg Roger L. Stevens, Chairman, John F. Kennedy Center for the Performing Arts, & Mrs. Stevens Henry S. Dogin, Acting Director, Office of Justice Assistance, Research & Statistics & Mrs. Dogin Mr. & Mrs. Hansen Bruce Kirschenbaum, Associate for Intergovernmental Affairs, & Mrs. Kirschenbaum Arnie Miller, Director of the Presidential Personnel Office, & Mrs. Miller Philip Anglim, Actor, New York City Dr. Richmond Crinkley, Director, Vivian Beaumont Theater, Lincoln Center, New York City (guest: Agnes Hardison) Stephen B. Farber, Executive Director, National Governors Association, & Mrs. Farber Penny Fuller, Actress David H. Gambrel, attorney, & Mrs. Gambrell, Atlanta Jack Hofsiss, New York City (Guest: Joan Hyler) Ms. Elizabeth McCann, McCann & Nugent, New York (Guest: Mr. Joshua Ellis) Mr. & Mrs. Set Momjian, Huntingdon Valley, Pa. Mr. & Mrs. Michael Murray, Salem, N.h. Nelle Nugent, McCann & Nugent, New York City (Guest: Mr. William D. Hartley) Ken Ruta, Chicago, Ill.