WASHINGTON - The Council on American-Islamic Relations (CAIR) Sunday called on the Republican leaders to repudiate racist taunts by the opponents of healthcare reform targeting a Muslim congressman and another African-American lawmaker on Capitol Hill. Congressman Andre Carson, a Democrat who is one of two Muslims in Congress, reported that protesters chanted 'nigger 15 times as he left the Cannon House Office Building with Congressman John Lewis, also a Democrat and a leader of the civil rights movement. Protesters also shouted bigoted slurs at other lawmakers, CAIR said in a statement. Vigorous debate on issues of importance to our nation is essential, but racist abuse like that used by the tea party protesters must be repudiated by all responsible leaders, said CAIR National Executive Director Nihad Awad, adding, We call on all those Republican leaders who addressed the protesters to take a public stand against such racist tactics. He said the United States must not let a vocal and bigoted minority 'turn back the clock on the Civil Rights Movement. Awad noted that the CAIR recently expressed concern about the reported rise in the number of anti-government and anti-immigrant extremist groups during the past year. Later, Michael Steele, the Republican National Committees first African-American chairman, called the incidents 'reprehensible.