NEW YORK, JULY 7 -- Democratic presidential candidates Bruce Babbitt and Michael S. Dukakis said today at the NAACP annual convention here that they oppose confirmation of conservative Appeals Court Judge Robert H. Bork to the Supreme Court.

Bork's confirmation has become a lightning rod for criticism at the 15,000-delegate convention and is increasingly being treated by civil-rights leaders as a political litmus test for presidential candidates and elected officials.

Chicago Mayor Harold Washington, speaking today, said that if Bork wins confirmation, "affirmative action is doomed."

"Have you heard a speech or two about Robert Bork so far?" former Arizona governor Babbitt asked. "Are you ready to hear another one? Because there can't be too many speeches about this nomination."

On Monday, Rep. Richard A. Gephardt (D-Mo.), another presidential candidate, denounced the Bork nomination as "a bad choice for America." Babbitt echoed that, saying Bork's constitutional philosophy is a threat to civil rights because he believes in the letter, not the spirit, of the law.

"We must have justices whose philosophies are consistent with that calling, and Robert Bork won't pass that test, I believe," Babbitt said.

Massachusetts Gov. Dukakis spoke briefly to a gathering of youth delegates tonight. He told reporters afterward that if he were a senator, he would not vote to confirm Bork. "I don't think you pick people who come from a very narrow ideological perspective and appoint them for life," he said.

Democratic presidential candidate Jesse L. Jackson is expected to appear here Wednesday.

NAACP executive director Benjamin L. Hooks said he originally invited only Babbitt and Jackson but has extended an invitation to other candidates to speak if they wish.

The first sign of the pressure the NAACP has vowed to exert on the Bork issue came today when NAACP board member and New York Democratic National Committeewoman Hazel N. Dukes introduced Sen. Daniel Patrick Moynihan (D-N.Y.) as a veteran NAACP supporter who would most certainly oppose Bork's confirmation.

Moynihan, however, said afterward that he would not say how he will vote on Bork.

"I have the votes in New York to defeat him," Dukes said when told of Moynihan's response. "When I get with his staff in New York, I'll get what I want. It's strictly politics."

New York Gov. Mario M. Cuomo, who was greeted warmly by the delegates, said, "Now today we're confronted with the possibility that the Supreme Court . . . may be about to turn back the clock."

The governor was not directly critical of Bork, but said after his speech, "It is wrong, in my opinion, for a judge to go on the Supreme Court . . . bench with his mind made up on abortion or any issues. If it becomes clear that he has already made up his mind, then he should not be on the bench.

"Can you call a strike before the pitch is thrown?" Cuomo asked. "How can you make a decision without reading the evidence?"

Bork's record opposing high court decisions in areas from affirmative action to abortion to voting rights, and his literal interpretation of the Constitution, have stirred opposition of civil-rights and feminist groups.

These Bork opponents fear that his replacing Lewis F. Powell Jr., who was often a crucial swing vote, would ensure a conservative majority on the Supreme Court.