President Carter steered his campaign across his driveway and into the Executive Office Building theater last night.It was as close to the hustings as he cared to get.

"This may have been his best campaign appearance until after New Hampshire," declared one White House adviser after last night's news conference. And the session was intended to be just that.

Carter had agreed to hold the press meeting at the urging of his chief political advisers in New Hampshire, including his deputy campaign manager, Chris Brown. They had argued that Sen. Edward M. Kennedy (D-Mass.) was making gains among New Hampshire Democrats with his attacks on Carter's decision not to campaign or debate as long as the hostages are being held in Iran.

Last night Carter was addressing the American public and the New Hampshire voters, talking of progress in the negotiations to free the hostages and launching his harshest attack as president against a political rival.

In the process, Carter also launched into several lengthy defenses of his decision not to debate or campaign now. "I didn't ask for a challenger, but I have no aversion to a campaign," Carter said . . . . I'm a campaigner. Obviously, it would be much better for me to be on the campaign trail . . . " And he said he would be there once the hostages are released.

There was only one pause in Carter's performance -- in fact, it was a pause and a gulp. It came when a questioner asked if he would also agree to debate Kennedy after the hostages are released. Carter made no promises.

Kennedy, in his attacks, has labeled Carter's style of politicking a "Rose Garden strategy" -- but the phrase did not originate with him.

In 1976, President Ford's aides, in a memo to their boss, outlined a strategy by which Ford would campaign largely through presidential news conferences. They called it the "no campaign strategy." But candidate Jimmy Carter, frustrated at being out on the campaign stump and the political limb, angrily dubbed it the "Rose Garden strategy."

Last night, the theater was filled, a sharp contrast with when Carter was holding televised news conferences at a regular, twice-a-month clip, and was playing to half-filled halls.

Last night there was an air of expectation as the president strode to the podium -- the sort of excitement there used to be on those rare occasions when Richard M. Nixon would venture out of the Oval Office to face the microphones during Watergate, and the sort of excitement there was when Gerald Ford would call a news conference to campaign against candidate Carter.

And when it was over, in the West Wing where the Carter advisers have their desks, the air of expectation and excitement continued. It was, in fact, something more.

Washington is a city that burns phrases like "cautious optimism" the way New Hampshire folks burn firewood -- but if ever there was a time to use that phrase, it was last night. For on the matter of the release of the hostages -- and its impact on American presidential politics -- Carter advisers are cautiously optimistic.

They believe the negotiations for releasing the hostages are moving toward successful conclusion -- and once that happens, Kennedy's attacks on Carter's reluctance to campaign will have been blunted in the best way possible. Carter will be able to show, dramatically and diplomatically, that he had steered the right course. And the one line of the Kennedy attack that has been most feared will have been shattered.

"It looks like a matter of days, not a matter of hours," one of Carter's senior advisers said in talking of how it appears that the hostages may be freed soon.

He was asked if it is likely to happen before the Feb. 26 New Hampshire primary. "I can't rule it out," he said, "but I can't be certain.'

Down the hall, another Carter adviser was reviewing the president's news conference as the political performance it was intended to be.

"Politically, it was a strong performance," this adviser said. "He looked good and strong . . . I just wish it could have been in the East Room."

But the East Room, laden with the trapping of the presidency, could not be used for this important presidential event. It was already booked -- for a Valentine dance for Carter campaign supporters from 27 states.