Vice President Gore and Bill Bradley appealed to minority voters in a debate here tonight by promising to put racial issues at the top of their agenda and seeking to outbid and discredit each other on diversity and civil rights.

Their testiest exchange of the hour-long debate came over racial profiling, with Bradley pointedly questioning why the Clinton-Gore administration has not taken action to ban the use of race as a factor in random searches by police.

"Al, I know that you would issue an order to end racial profiling if you were president of the United States," Bradley said. "But we have a president now. You serve with him. I want you to walk down that hallway, walk into his office and say: 'Sign this executive order today.' "

Gore shot back: "I don't think President Bill Clinton needs a lecture from Bill Bradley about how to stand up and fight for African Americans and Latinos in this country. It's one thing to talk the talk. It's another thing to walk the walk."

Gore and Bradley, two Democrats with strong records on race, agreed broadly on most issues during the televised "Black-Brown Forum" held on the federal holiday honoring the Rev. Martin Luther King Jr., but their sometimes hostile rhetoric underscored the high stakes of the caucuses to be held here in a week.

Bradley, who trails Gore in polls in this state but is tied in a new poll for the Feb. 1 New Hampshire primary, backed off one of his most controversial positions, which called for adding gays to the protected classes of the 1964 Civil Rights Act.

His stand had been criticized by civil rights leaders and gay activists who fear reopening the act in a Republican-led Congress would lead to fewer protections for minorities. During tonight's debate, moderated by Tavis Smiley of Black Entertainment Television, Gore revived the criticisms, suggesting Bradley's approach "could lead to it [the law] being seriously damaged and even lost." Bradley then tempered his earlier position: "Now, would I send such a piece of legislation to Congress if I thought the 1964 Civil Rights Act was going to be opened up? Absolutely not."

The two candidates revealed subtle but significant differences when asked about Al Sharpton, an African American political activist in New York who has made statements regarded as antisemitic and anti-white, and John Rocker, the white Atlanta Braves pitcher who disparaged minorities, gays and immigrants in a recent interview in Sports Illustrated. He has been ordered to undergo psychological testing by Major League Baseball.

Bradley, after twice calling him "John Rooker," called for harsh treatment of the pitcher, adding, "I wouldn't be disappointed if they fired him." The former New Jersey senator was far more forgiving of Sharpton and defended his trip last year to the black leader's Harlem neighborhood.

"I don't agree with Al Sharpton on everything, but I think that he's got to be given respect, and people have to be allowed to grow," Bradley said. "It's a sad time when we don't look at somebody as they move through life, and we get them stuck at a particular position in life."

Gore, on the other hand, has refused Sharpton's entreaties for a public visit, although he noted tonight he did meet privately with Sharpton last year. Referring to today's commemoration of King's birthday, Gore struck a chord of forgiveness in the case of Rocker, who he said has met with former Atlanta mayor Andrew Young and baseball legend Hank Aaron. "I think that America is all about redemption and part of the message of Dr. King is to love your enemies and plant the seeds of reconciliation in their hearts," the vice president said.

The two candidates seized on the refusal of the GOP presidential candidates to denounce the flying of the Confederate battle flag over the South Carolina capitol. Bradley, calling the flag an "offense to our common humanity," did not reply to the more difficult question of whether he would join the NAACP's boycott of the state. Gore said: "I do not think a president of the United States should ever boycott an individual state because the president needs to bring our people together and we need to bring the Confederate flag down."

In this state, where Hispanics now substantially outnumber African Americans, Gore and Bradley both promised to appoint Latinos to prominent government posts. Gore was equivocal in his response to the question of whether he would appoint the nation's first Latino Supreme Court justice and Bradley said: "No commitment today, but commitment that there are many who could."

On the fate of Elian Gonzalez, both Democrats refused to say whether they believe the young Cuban boy should be sent back to his father in Cuba or remain with other relatives in the United States.

The candidates showed a willingness to review current law prohibiting convicted felons from voting. Gore said he would not lift the prohibition for violent criminals under any circumstances. Bradley said that in the case of a nonviolent offender who "comes out and is able to go straight for two years, three years, I think that that person ought to be able to wipe his record clean and start the day anew."

He was also critical of disparate sentencing between blacks and whites and called for equalizing penalties for crack, which is more prevalent in the minority community, and powder cocaine, found more often in white areas.

Both Bradley and Gore marked the King birthday during the morning, Gore in Atlanta, Bradley here in Des Moines.

During a service at historic Ebenezer Baptist Church, Gore wrapped much of his stump speech in the legacy of the slain civil rights leader. He even managed to link King to his ongoing assault on Bradley's health plan, a proposal Gore says jeopardizes the Medicare and Medicaid programs. "And I see a day when we strengthen Medicare and Medicaid--which were created during Dr. King's lifetime, and must not be torn down in ours," Gore said in a low-key 15-minute address.

With former Boston Celtics star center Bill Russell at his side, Bradley appeared at two King birthday events--one sponsored by Iowa Gov. Tom Vilsack (D), the other a discussion of race at Drake University.

Although Bradley has been critical of the Clinton administration's ethical standards, he went out of his way to link himself to Clinton's racial stands. On race, he said: "I'm more similar to Bill Clinton than I am to any other politician." Polls show that Clinton continues to receive some of his highest favorability ratings from African Americans, and this support is reflected in Gore's decisive margins over Bradley among black voters.

Bradley told the students: "It is your generation that can blow away the acrid smell of racial discrimination. . . . We are at a time when we have the opportunity to reconstruct the racial question that made such progress in the 1960s." Child poverty and child health care are the issues on which to build a new, multiracial coalition, he said.

Staff writer Ben White contributed to this report.

CAPTION: Democratic presidential candidates Bill Bradley and Vice President Gore take their places before Des Moines debate.