One of the underlying messages of the Kennedys-King Day affair held last week by the D.C. Democratic State Committee is that the titular head of the party, Mayor Walter E. Washington, is extremely titular party head, indeed.

The mayor missed the morning breakfast, at which he was supposed to give the city's greetings, but few of those present appeared to miss the mayor. He did attend the $100-a-plate dinner that evening but few if any members of his cabinet were there.

When the mayor addressed the audience, he fired a couple of strong verbal salvos at his political opponents. And he left some of the party members shaking their heads after he virtually admitted his own shortcomings by saying, "You can't worry about the problems. You just do the best you can. You understand what I mean." Afterward, several said that they did.

For the past year, the mayor has been on the outs with the party, ever since his Open Party slate got clobbered by the Unity '76 coalition in the face for control of the state committee. The leaders of the winning slate, including City Council Chairman Sterling Tucker, are now among the mayor's strongest critics and major political opponents.

Did the mayor have wishful thoughts about the light-hearted remarks of Housing and Urban Development Secretary Patricia Roberts Harris? She joked that she had seen Washingon pull what appeared to be a wand from his pocket, wave it in the air and - poof! - Sterling Tucker disappeared.

For all the great pre-dinner fanfare about White House commitments to a good show at the Kennedys-King Day dinner, the actual turnout from 1600 Pennsylvania Ave. was a little less than brilliant.

Secretary of State Cyrus Vance spoke only 10 minutes, WHite House assistant Hamilton Jordan didn't show nor did either of the Carter administration's two major liaisons with the Distrcit - presidential assistant Martha (Bunny) Mitchell (a former state committee member) and James Dyke of Vice President Mondale's staff.

Former D.C. School Supt. and now City Council candidate Barbara Sizemore did show, but only for breakfast and dinner. She missed the lunch at which, coincidentally, her successor, School Supt. Vincent R. Reed, was honored.

In some ways, it was a born again D.C. Democratic Day, with the day-long schedule and optional black-tie dinner in the style of the Carter administration. But one of the senior citizens noticed an important ommission on his breakfast plate.

"They must not have known we were coming," he told a friend. "There aren't any grits."

Marion Barry says he is confident that there was no conflict of interest when he called Environmental Services Director Herbert Tucker recently to ask a meeting on behalf on Pride Environmental Services, which has a city contract to put trash cans and also has Marion Barry on its board of directors. Barry wanted to work at 'some problems' which he won't explain.

Just to make sure there was no misunderstanding, Barry, who has persistently been hounding Tucker about the city's method of issuing and collecting water bills, said he wanted to meet not as a City Council member, but as a member of the board of Pride.

Tucker, after checking with city administrator Julian Dugas, said no way. Now Barry has written a memo to Dugas which the Council member refused to disclosed to the press.

It is not a conflict of interest, Barry asserts. He gets no money from his board membership, and he was not trying to get the city to give Pride a contract. "In this situation," Barry says, "everybody is conveniently using conflict of interest as an excuse not to do anything or to raise questions about it."

Nice to be back on the inside after some cool months on the outs. There in the VIP section with the City Council members and department heads for the arrival of Princess Anne at the District Building last week was Norval Perkins. The former city elections chief is now on the job regularly as executive director to the Gambling Study Commission. Details are still being worked out on $18,000 in back pay the city owes Perkins as a result of the abortive effort by the elections board to fire him.