There was a time when former mayor Walter E. Washington appeared unwanted and unappreciated -- a politician under siege who hadn't been given enough credit for weathering the riots of 1968 or helping to usher the District of Columbia into a new era of home rule.

In the twilight of his 11 years in office, Washington, a friendly, talkative, immensely likable man by nature, was reduced to dodging reporters' persistent questions on the controversy surrounding one of his top aides, Joseph P. Yeldell. He was stung by criticism that he was an inept administrator -- a "bumbler and bungler" in the words of Marion Barry, who defeated Washington in 1978 in a three-way Democratic primary race for mayor.

But recently, after three years of relative obscurity as a corporate lawyer here for a New York City-based firm, the former mayor has happily reemerged as a political force who may shape the outcome of next year's potentially fractious Democratic primary.

"That man is a power to be reckoned with," City Council member David A. Clarke (D-Ward 1) observed. "He continues to carry a lot of good will in this community, and whoever he chooses to bless (in the mayor's race) is truly blessed."

Washington pooh-poohs any suggestion that he could act as a power broker in 1982.

"I'm not trying to offer myself as a king-maker -- just a good citizen," Washington insisted this week.

But Washington's new-found political clout could hardly be mistaken at a reception held in his honor last week at the plush Four Seasons Hotel in Georgetown. The evening affair attracted the cream of the city's political, business and labor leaders including Barry, Washington's erstwhile critic.

"This is just a fun night," Washington gushed as he was wooed and flattered by Barry; City Council member Betty Ann Kane; Robert E. Petersen, president of the Greater Washington Central Labor Council; John R. Tydings, executive vice president of the Greater Washington Board of Trade; politically active lawyer R. Robert Linowes; and scores of others.

When one of the organizers of the reception tried gently to tug a Washington Post reporter away from where Washington was chatting with some friends, the former mayor objected. "Leave him be," Washington said. "He hasn't asked me any good questions yet."

While a combo played "It Was Just One of Those Things" and 120 or so guests munched hors d'oeuvres and sipped cocktails and wine, Washington moved effortlessly from one corner of the dining hall to another, pumping hands, occasionally embracing an old ally and swapping stories and small talk.

The gathering consisted primarily of old campaign hands, longtime friends, a few of the heavy-hitting businessmen who had been mainstays in the Washington campaign -- until after he lost the primary -- and many from the new and younger emerging political elite.

There was real estate executive Flaxie Pinkett, former city planner Ben W. Gilbert, ward activists Harry Thomas and Lillian Huff and lawyers John R. Risher Jr., John A. Nevius and Clinton W. Chapman and his wife Charlotte -- Washington's old friends and colleagues.

From the business community came Joseph H. Riley, chairman of National Savings & Trust Co.; WMAL radio executive Andrew Ockershausen; former police chief Maurice J. Cullinane, now a lobbyist for the city's bankers; Luther Hodges, the chairman of the National Bank of Washington; and developer Theodore R. Hagans Jr., who after Washington was defeated became chairman of Barry's inaugural committee.

Among the new breed on hand were Council members Clarke, Charlene Drew Jarvis and H.R. Crawford and several Barry aides as well as the mayor's wife Effi. Even laywer Robert B. Washington Jr., who along with former City Council chairman Sterling Tucker tried unsuccessfully in 1977 to woo Washington out of office early with the lure of an ambassadorship overseas, was on hand for the gala.

The 66-year-old former mayor seemed to be in his glory and enjoying his role as a not-too-elder party statesman and a bridge between the city's sometimes warring business and labor communities -- the same kind of role many thought he was most comfortable with during his 11 years in office.

Though forced in 1979 to relinquish the trappings of public office that he always relished, Washington has found that there is life after city hall, even though he has traded in his chauffeured sedan for a Cadillac that he usually drives himself.

He sits on the boards of Woodward & Lothrop, the National Permanent Federal Savings & Loan Association and the the District Realty Title Insurance Corp. He also is a governor of the International Club of Washington and belongs to the tony Cosmos Club.

Washington took advantage of the reception at the Four Seasons to make his pitch for party unity. He warned that a bloody, divisive Democratic primary battle next year could cause unforeseen damage to the city's uphill battle for true legislative and budgetary independence from Congress by providing ammunition to perennial critics of home rule.

"I don't believe we can long survive if we're not together politically," Washington told the group. "I'm not running for anything, so I can say what I want. As we go into the campaign, we must not cut each other up in the eyes of the city or in the eyes of the country. . . . We've got something greater than an election going for us in this city."

Washington's political homily was greeted with a few amens and a lot of applause. Certainly the message wasn't lost on Barry, whose narrow victory over Washington and Tucker with 35 percent of the Democratic primary vote may have been a cakewalk compared to the upcoming election. And this time it will be Barry's record, not Washington's, that will undergo intensive scrutiny.

From Barry's point of view, a kind word or two from Washington certainly couldn't hurt, especially among the kind of labor, business and church groups that felt at home with Washington and are still not sure about Barry. But for the time being, Washington is remaining tight-lipped as to where he stands.

"It's got to shake down first," Washington explained. "I've got to find out if all of (the candidates) are in to stay, or are just in." Walter Washington still has a gift for keeping people in suspense.

Washington insists that he bears no grudge toward Barry, despite some of the unkind things that were said about him three years ago.

Nevertheless, he couldn't pass up the opportunity at his reception to remind the nattily dressed mayor and other black office holders that it was Walter Washington who blazed the city's difficult political trails.

"The city has come a long ways," Washington said. "We brought it out of the ashes. And many of you in three-piece suits are better off because of it."