"Washington is a the same time the most partisan town in the country and the most nonpartisan," Bruce Sundlun said last night as he surveyed the mix of Reagan insiders, Democrats and media people who gathered at the Organization of American States building for a party in honor of Robert Keith Gray.

"If you're a real Washington pro, party lines aren't terribly significant," said Sundlun, chief executive officer of the Oultet Co.

Gray has been called the ultimate Washington operator and the 80 guests who attended the party given for him by Alejandro and Helga Orfila attested to his drawing power.

Sen. Paul Laxalt (R-Nev.), the president's personal friend and "point man" in the Senate, was there, as were longtime Reagan friend Nancy Reynolds; Secretary of Health and Human Services Richard Schweiker; special assistant to the president Helene von Damm; Rose Mary Woods, former president Nixon's secretary whom Gray often squires around; Anne Wexler, an assistant to former president Carter, and her husband Jospeh Duffey, chairman of the National Endowment for the Hummanities; Mayor Marion Barry; and columnists William Safire, Carl Rowan and Rowland Evans.

Eight days ago Gray left his job as head of the Washington office of Hill & Knowlton, one of the world's largest public relations firms, bought the Powerhouse building in Georgetown and launced his own firm.

But last night's party wasn't in honor of his new job.

"We toasted that over the phone all week," Nancy Reynolds said.

The party was given "because he's a very good friend, he did a very good job [as co-chairman] with the inauguration and because he knows everyone in Washington -- he's introduced me to a lot of people," Orfila said. "He's helped open a lot of doors to me."

In addition to talk of how long everyong has known Gray (C. Wyatt Dickerson said his wife, Nancy, dated Gray years ago when Gray was working in the Eisenhower White House), the conservation at the party was dominated by discussions of Reagan's proposed budget cuts and the administration's policy in El Salvador.

"There'll be a lot of discussion on the Hill about the cuts, but I think the bulk of the package will pass, mainly becaused the people will insist on it," Laxalt said. Popular support is definitely behind the cuts, he said, but it is "more mixed" on the issue of aid to El Salvador.

Duffey, whose agency's budget is scheduled to be reduced by 50 percent, called the cuts "unpleasant and difficult." He said "some cuts are in order, but 50 percent isn't taken from a careful look at the programs, and I wrote a letter to [OMB Director David] Stockman saying so."

Schweiker called the proposal cuts fair. "In my own department only 3 1/2 percent -- $9 billion -- is being cut out of a budget of $250 billion. It's still bigger than any country in the world and larger than the Defense Department's."

On the topic of sending American aid to El Salvador, Schweiker called Reagan's position "sound." I think he is taking the Vietnam experience with him. He learned from Vietnam, we all did. You can't fight somebody else's war, you can only help them. We made the mistake in Vietnam of trying to fight for them -- all you can do is assist."