Last Saturday's D.C. Democratic Party delegate-caucuses had a light-hearted flavor, with lots of speech-making, sign-waving and political one-upmanship. But beneath the fun was a more serious test of the organizational talents of the two major preidential campaign committees.

Competition at the caucuses, held to choose slates of delegate candidates for May 6 Democratic Party primary, was evident at several levels.

The most visible showdown was over whether President Carter or Sen. Edward M. Kennedy would bring out more supportes on a cold, blustery Saturday. Kennedy won, drawing 690 Democrats to his caucuses as opposed to 544 for Carter.

Another competition was over which slate would list more well-known officials and party leaders whose names could add clout in the primary. In this contest, neither camp took any chances, despite disclaimers that slots on the ballot slates were open to anyone who choose to run.

Before the caucus for Wards 3, 4, 5 and 7, held at Dunbar High School, the Kennedy delegate candidates met to develop a slate that was carefully balanced by sex, race, ward and degree of political influence.

The Kennedy slate, listed in handouts distributed at the door, included D.C. Delegate Walter E. Fauntroy, who lives in Ward 4 and has substantial backing there in addition to his city-wide reputation; Washington Teachers Union President William H. Simons, who is expected to bring at least some teachers with him to the Kennedy camp; gay activist Frank Kameny, who is expected to bring with him the powerful gay lobby; Lillian Huff, a former Democractic National Committeewoman who swithched sides after being an early supporter of Carter in 1976; and realtor Flaxie Pinkett, who is expected to appeal to oldline blacks in Wards 4 and 5. All won slots on the May 6 ballot.

Just before it was time for the assembled Democrats to vote, Marilyn Brown, who chaired the Kennedy caucus, read the slate. She reminded everyone that the Carter folks had already developed a slate of their own that listed "a number of elected officials." The message was clear.

The Carter contingent at the Dunbar caucus had also developed a slate designed to winnow out at least some of the political "heavies" who wanted to run as Carter delegates.

During the last presidential primary in 1976, Fauntroy and then mayor Walter Washington headed rival 13-person slates of uncommitted delegates. Both slates were worked out before the caucuses.

This year, however, a number of elected officials filed early to run as delegates. With the exception of city council member John Wilson (D-Ward 2), all major D.C. Democratic officeholders have declared a preference for either Carter or Kennedy.

The City Council members from the four wards -- Polly Shackleton, Charlene Drew Jarvis, William R. Spaulding and Willie J. Hardy -- are all Carter supporters. They talked before the caucuses and developed a slate headed by Jarvis, Spaulding, National Committeeman John Hechinger, party chairman Robert B. Washington Jr. and State Committee member Florence Pendleton. All were elected.

Hardy, National Committeewoman Sharon Pratt Dixon -- wife of Council Chairman Arrington Dixon -- and organizer Kimi Gray were among the influential Democrats who agred to drop out of the race.

Special interest groups also did some slate-making for the caucuses. The D.C. Women's Political Caucus successfully slated candidates for both the Carter and Kennedy caucuses.

The best organized were the gay rights groups who ran shuttle buses to the caucus sites and managed to elect their entire slate in the Kennedy caucus for Wards 1, 2, 6 and 8, held in Georgetown University Law Center. Spokesmen claim that 75 percent of the persons at the Georgetown Law Center Caucus were there to vote for the gay slate.

As a result, the delegate slates will include familiar names that presumably could help sway undecided voters May 6.