Black and Jewish political leaders voiced concerns yesterday that the defeat of Rep. Cynthia McKinney (D-Ga.), a critic of pro-Israel policies, by a challenger receiving extensive Jewish support might intensify ill feelings between two important Democratic constituencies. Any increase in tensions between Jewish and African American voters, political activists said, could damage Democratic hopes of taking back the House and keeping control of the Senate.

Aided by hefty contributions from Jewish donors and big vote totals in predominantly white precincts, former state judge Denise Majette soundly defeated McKinney -- 58 percent to 42 percent -- in Tuesday's primary in Georgia. Majette is strongly favored to win the Nov. 5 general election in the solidly Democratic district near Atlanta.

Although both Majette and McKinney are African American, the unusual interest in their primary by pro-Israel groups backing Majette and by pro-Muslim groups backing McKinney triggered talk yesterday of a potential for sharpened conflicts between blacks and Jews -- in Georgia and elsewhere.

Rep. Eddie Bernice Johnson (D-Tex.), chair of the Congressional Black Caucus, said that "at the grass roots" among African American voters, there is a growing perception that "Jewish people are attempting to pick our leaders. . . . There is some concern about that. It's concern about any candidate being targeted by a special-interest group for voting on any one issue."

McKinney, a frequent critic of pro-Israel policies, received substantial campaign donations from Arab and Muslim sources outside her district.

Also influencing the outcome was a strong white turnout for Majette, a failure by McKinney's campaign to produce high turnout among supporters and a split among Atlanta's most prominent blacks. Several of them -- including former Atlanta mayor Andrew Young and baseball's home run king, Henry "Hank" Aaron -- declined to endorse McKinney.

In her concession speech, McKinney said, "It looks like the Republicans wanted to beat me more than the Democrats wanted to keep me."

Many Republican voters took advantage of Georgia's open primary system to cast ballots against McKinney in the Democratic contest. McKinney infuriated many Republicans this year by suggesting that President Bush might have known in advance about the Sept. 11 terrorist attacks and did nothing because his associates in the defense and energy industries stood to profit in the aftermath.

In some majority-white precincts, McKinney lost by more than 30 to 1. In the Kingsley precinct, Majette received 1,012 votes to McKinney's 30. In the Austin precinct, it was 1,123 to 33.

It was the Jewish-Muslim conflict, however, that dominated much of the post-election reaction. In a TV interview on election eve, McKinney's father, state Rep. Billy McKinney (D-Atlanta), was asked to explain why his daughter was in a tough fight. He spelled out his answer: "J-E-W-S."

The McKinney-Majette contest is the second House Democratic primary this year in which an African American incumbent who had taken controversial stands sympathetic to Palestinian and Muslim causes was ousted by a lesser-known black challenger financed heavily by out-of-state Jewish donors and pro-Israel PACs. In Alabama, Rep. Earl F. Hilliard (D) lost to Artur Davis. Davis and Majette raised and spent more than $1 million each, more than McKinney or Hilliard.

Some Democratic strategists privately suggested the party will benefit in some respects from McKinney's and Hilliard's losses, along with the departure of House Democratic Whip David E. Bonior (Mich), who lost a gubernatorial bid, and Rep. James A. Traficant (D-Ohio), who was expelled and sent to prison. "These guys were thorns in the side of the Jewish community and cited repeatedly by Republicans trying to get Jews to quit our party," one Democrat said.

Jesse Jackson, founder of the Rainbow/PUSH Coalition, does not share this view. He said Democrats must preserve the coalition between blacks and Jews because they support much of the liberal agenda and are crucial to many Democratic candidates.

However, Jackson said, referring to a prominent lobbying group, the American-Israel Public Affairs Committee: "It seems AIPAC's position now does not place a great premium on that coalition." All pro-Israel efforts this year to defeat incumbents have targeted blacks, he said, while leaving white congressional critics alone. "That is true and deeply troubling," Jackson said.

But some sources active in the pro-Israel camp said the next likely target is Rep. John E. Sununu, a white Republican who is challenging Sen. Robert C. Smith in New Hampshire's Sept. 10 GOP primary.

Ira N. Forman, executive director of the National Jewish Democratic Council, said of McKinney's defeat: "One of the most antagonistic persons -- if not the most antagonistic person -- to the U.S.-Israel relationship is gone." He said the political consequences "remain to be seen" and that he is concerned about "tension between some in the black caucus and the Jewish community. But their long-term interests are together."