The Carters had 1,000 blacks over on the South Lawn yesterday for what some might have called a swampy tea party, but most would have labeled a bid for the minority vote.

"I went into the White House and just acted like a queen and a duchess," a young Community Services Administration clerk named Marseeiah Gordon was saying as her high heels sank into the muddy grass. "You know, you sit down and sort of curtsey. I think it was in the Red Room."

"You are a trip, girl," another CSA employe named Joseph Reid told her.

As it happens, she's voting for the president and he's not.

"I'm not going to vote for Carter just because I came to the White House," Reid explained during a break from posing for Instamatic snapshots in front of the South Portico. "I basically don't think he's delivered on his promises."

Yesterday's event for a Blacks in Government conference was another in a constant stream of White House parties for important Carter constituencies. How effective these are in producing actual votes from the comments, camera clicks and awe under the trees yesterday, this one didn't hurt.

For instance: Over in a spot of muggy sunshine, Eugene Chandler, an equal employment officer from the U.S. Army with a thick head of gray hair, was taking a picture of Constance Clayton, a computer systems analyst from the Department of Health and Human Services. Her blue silky dress and white pearls set off the White House nicely while she explained that pre-tea party she didn't know who she was going to vote for, but apres-tea party, the choice was clearly Carter.

And why? Well," she replied, gesturing toward the stage where Rosalynn Carter had spoken moments before, "she's a gracious hostess."

In her remarks, Rosalynn Carter reiterated the president's committment to blacks, and then afterward, made her way through a wiggling receiving line. "I don't think she's ever seen so many black folks before," one young guest said to a friend.

The crowd, which was part of a local three-day conference held by this 10,000-member organization that wants to advance the welfare of blacks in government, appeared to be mixed in its support of the president. "I think this is a curiosity crowd," said Lonis Ballard, the organization's president. t"It's people who haven't been to the White House before.

"I think most blacks feel that Carter's a sensitive man," Ballard continued, " and that he has somewhat of a feeling of what blacks have been subjected to. However, in the feeling of some blacks, in my opinion, all of his promises have not been delivered on."