There has not been a black Republican House member since 1934, but Charles Black, chief Republican Party spokesman, predicted the GOP will "defy history" in November and elect the three conservative black Republicans he introduced at a news conference yesterday.

In Ohio, J. Kenneth Blackwell, a former mayor of Cincinnati and a deputy undersecretary of Housing and Urban Development under Jack Kemp, and in Connecticut, Gary A. Franks, a three-term alderman in Waterbury and owner of a real estate investment firm, are running for open seats in districts that President Bush swept in 1988. Al Brown, founder of a management consulting firm, is challenging Rep. Romano L. Mazzoli (D-Ky.), a 20-year incumbent who won his three-way primary with only 45 percent of the vote.

Blackwell is leading Democratic nominee Charles Luken, the son of Rep. Thomas A. Luken (D), who is vacating the seat. Blackwell spoke out yesterday for spending cuts and against the 1990 civil rights bill, which he called "too reliant on quotas."

Franks, a self-described "fiscal conservative," is painting his opponent, former representative Toby Moffett (D-Conn.), as "a tax and spend liberal of the '70s." He called Moffett, who moved into the district last January, "an opportunist." Franks said polls show the race "a dead heat."

Brown, running in a Democratic district, is campaigning on an anti-incumbent theme. He called Mazzoli "one of the worst congressmen . . . he epitomizes the sickness" of the institution. Brown said Mazzoli has "voted for every tax increase."

The three candidates played down race as an issue in their campaigns. "Our electorate is not looking to see what color we are but who stands to do more for our communities," Brown said.