J.C. Watts, only black Republican in Congress, calls its quits.(Chicago Tribune)

WASHINGTON _ Oklahoma Rep. J.C. Watts, the only black Republican in Congress and one of the party's congressional leaders, announced Monday that he is retiring, handing Republicans a setback at a time when the GOP has been trying to increase its diversity and reach out to minorities.

Watts' departure, amid talk that he was frustrated at being shut out of important decisions, leaves the GOP without a high-profile African-American leader and only a handful of black Republican politicians in the pipeline.

"They know they have a problem, and it's a long-term problem," said David Bositis, an expert on black politicians and voters at the Washington-based Joint Center for Political and Economic Studies.

From the moment he arrived in Congress in 1995 when Rep. Newt Gingrich, R-Ga., took over as speaker at the start of the "Republican Revolution," Watts has enjoyed a bonanza of attention. He was frequently showcased at Republican news conferences, and in 1996 he was chosen to speak at the GOP national convention. The following year he gave the party's response to President Bill Clinton's State of the Union address.

Watts' departure could have major political ramifications for the GOP.

Republican leaders acknowledged they have a problem. "There's an understanding we have a lot of work to do," said Republican National Committee spokesman Jim Dyke. "We just have to continue to focus on one positive agenda that affects all communities and the African-American community as well, and hope that provides us with an opportunity for others to take a second look at the Republican Party."

Still, Republicans insisted they are making inroads with minority voters, and they played down the notion that Watts' action means anything about their party's relationship with minorities, saying his leaving was a deeply personal decision about his family.