With overzealous supporters perhaps responsible for two defeats already, D.C. Del. Walter E. Fauntroy said yesterday that he would seek to slow down the drive for ratification of the constitutional amendment that would give voting representation in Congress to the District.

Fauntroy also pledged a moratorium on local activity in behalf of the amendment until after the Sept. 12 Democratic primary in the city. He expressed concern that the issue could lose some of its widespread bipartisan support if it got caught up in the hotly contested mayoral race.

Trying to put the best possible light on setbacks in the legislatures of California and Delaware, Fauntroy said lessons learned (there) will enhance chances" for eventual ratification of the amendment by the necessary 38 states.

One of the lessons learned from actions in those two states, Fauntroy said, was that each state legislature will have to be lobbied in a manner similar to the successful campaign that got the amendment through Congress earlier this year.

In both California and Delaware, supporters within those legistures attempted to waive rules that require hearings on bills, and as a result, hoped-for early ratification was turned down.

Fauntroy learned about the two defeats during a 24-hour round trip to California. By the time he arrived in Sacremento early Thursday, the state Senate had refused to waive the rules. When he got off the plane at National Airport Thursday night on the return trip, he was greeted with the report that the Delaware legislature also had turned down a request to waive the rules. Fauntroy was not even aware the Delaware assembly had been asked to move on ratification.

The next state that may consider ratification is Michigan, whose legislature meets next week, Fauntroy a is hw qouls not attempt to call off plans to have the amendment introduced in Lansing, but he hoped to avoid any attempt to suspend rules and get a quick vote.

"We'll need time to build a broad base of support," Fauntory said at a press conference in the Rayburn House Office Building. The same "coalition of conscience . . . black and white, Republican and Democrat, city and suburban, urban and rural" that guided the proposal through Congress would be sought, he said.

Another concern expressed by Fauntroy involved a story in an Atlanta newspaper in which Georgia legislator Julian Bond was quoted as saying that after ratification, he planned tomove to the District and seek one of its Senate seats.

Fauntroy said he planned to contact Bond "to make sure his comments were made in jest."

Similar stories about Rep. Ronald V. Dellums (D-Calif.) Jesse Jackson and other nationally known black leaders being major beneficiaries of the amendment were circulated by opponents of ratification during last week's consideration of the resolution by the California legislature.

"Anyone who stresses this as a black issue is undermining the cause," Fauntroy said.