The Republican, the Socialist and the Independent were there. But the Democrat, Mayor Marion Barry, failed to show up last night for a debate with his challengers for the mayor's job in next Tuesday's general election.

"When Patricia Harris didn't show up for a forum, Marion Barry always said the same thing and I'm going to quote him tonight," said Dennis Sobin, the independent candidate. " 'Regardless of who you vote for in this election, you should not vote for anyone who is not here because if they won't come out and face the voters before the election they won't come out and face the voters after the election.' "

E. Brooke Lee, the Republican, held up a large sign to the group of about 40 persons in the City Council chambers. The top of the sign read: "Hey Marion, Why Don't You Come Out and Debate? People Are Asking Me About the Bates Housing Development, Pride . . . the Voter Registration Rolls."

In addition to Sobin and Lee, Glenn B. White, the Socialist Workers Party candidate, took part in the hour-long debate, which was moderated by Dr. John Womble, a write-in candidate for mayor who is head of the martial arts department at the University of the District of Columbia.

White and Lee offered widely opposing views during most of the debate. While Lee promised to bring more jobs to the city because of his affiliation with several companies, White said unemployment is a national problem and no candidate can fulfill a promise to bring jobs to the city.

"If he has the key to Exxon, then the man should go and bring the jobs in here yesterday," said White.

White proposed that the city begin a public works program to hire the unemployed. He added that the city government's pleas of being unable to fund such a program because of financial problems were "ridiculous" in light of Barry's ability to raise $1.2 million for a political race.

Lee, Sobin and White offered differing reactions when they were asked for their positions on the statehood constitution that will be on Tuesday's ballot. Lee opposes it as a "socialist document aimed at redistributing wealth." Sobin favors it as a "progressive document," and White said his party urged voters to abstain because big companies would still run the city.