Out on the town meeting the neighbors for the second night in a row, Ronald and Nancy Reagan took their traveling love fest last night to Capitol Hill, where Sen. and Mrs. Howard Baker gave a dinner for them at the Library of Congress.

And how sweet it was.

Everywhere anybody looked were Republican senators -- or senators-elect -- trying to get used to being important again.

"This is a family party -- this is the Republican Senate, the most effective political unit in this city," Baker reminded them just in case it hadn't yet sunk in, and in the process smiled so much that, as he told somebody earlier, his jowls hurt.

Whose didn't?

There was Sen. Barry Goldwater's I-told-you-so smile remembering Ronald Reagan's political debut at the 1964 GOP convention. "Maybe I got him started," he said of the former California governor, who delivered a fund-raising speech for Goldwater.

There was Ronald Reagan's smile of gratitude, remembering it, too: "A prophet in his own time saying we could return government to the people," he told the crowd in an after-dinner tribute to Goldwater. "If he hadn't walked that lonely road, some of us wouldn't be here tonight."

There was Sen. Strom Thurmond's determined smile: He takes over the judiciary committee when the Republicans assume majority status in the Senate next year. "We're going to turn this country around," said the South Carolinian. "We're going to protect the civil rights of everybody in this country."

There was Sen. John Tower's enigmatic smile; he is being mentioned as a possible secretary of defense. Does he want that post? "A very leading question," he said.

There was retiring Sen. Richard Schweiker's win-a-few, lose-a-few smile. "My timing's bad," said the Pennsylvanian, who would have been Reagan's running made had Reagan won the 1976 GOP nomination."I ran too soon for vice president four years ago, and now I've retired too soon from the Senate."

And there was Sen. Ted Stevens' love-in-bloom smile as his forthcoming Dec. 30 marriage to former Fairbanks, Alaska, district attorney Catherine Chandler was announced by Baker.

Those and more smiles surrounded the Reagans, who arrived with Vice President-elect George Bush and his wife, Barbara, shortly after 7 p.m., bringing along some smiles of their own, of course.

Among the crush were 10 out of 16 new senators, including New York's Alfonse D'Amato, South Dakota's Jim Abdnor, Alabama's Jerry Denton, North Carolina's John East, Iowa's Charles Grassley, Florida's Paula Hawkins, Indiana's Dan Quayle, New Hampshire's Warren Rudman, Pennsylvania's Arlen Specter and Idaho's Steve Symms.

If newcomers were talking about hoped-for committee assignments, veterans were running around pinching themselves.

"I still haven't come down off cloud nine," said Sen. Robert Packwood, destined to become Commerce Committee chairman, a sentiment articulated in a variety of ways by others like Sen. Pete Domenici of New Mexico and Sen. Bob Dole of Kansas.

"It's a great new world out there for Republicans," said Dole, groping for a way to put it and ending up more nearly speechless than anyone could ever remember.

After dining on consomme, beef stuffed with truffles, spinach ring and carrots and lemon souffle with fresh strawberries (like the wine, from California), everybody settled back to wallow in their win.

Baker said he remembered the enormity of the realization on election night that the GOP was going to win not only the White House but very possibly the Senate. He called Dole and asked if he'd figured out yet that he might be the next Finance Committee chairman.

"An Dole said, 'Yeah, but who's going to tell Russell Long?'"

"What do we all do for an encore?" asked Sen. John Heinz of Pennsylvania, whose handling of the Senate campaign committee purse strings, according to Baker, probably did more than anything else to create the first Republican Senate in 25 years.

"You can elect a Republican House," answered Reagan a little later.

There was a standing ovation for Sen. Paul Laxalt of Nevada, Reagan's campaign chairman and, as Baker put it, the man who created the victory.

And another for Ronald Reagan.

"Since Nov. 4, Nancy and I have been saying to each other, 'When is it really going to sink in?' Today," said Reagan of his daylong sojourn among them on The Hill, "you have driven it in."