LAS VEGAS — Democratic presidential rivals Hillary Rodham Clinton and Barack Obama jointly pledged to bury a rancorous debate over race Tuesday night, each agreeing in a nationally televised debate that the other had long favored civil rights.

Both blamed supporters for some of the anger that had seeped into their competition for the party's presidential nomination in recent days.

"We both have exuberant and sometimes uncontrollable supporters," Clinton said in the opening moments of a two-hour debate televised on MSNBC.

Obama said both have "supporters or staff who get overzealous. They start saying things that I would not say."

Clinton, Obama and former Sen. John Edwards sat down for their debate as the former first lady won a meaningless Michigan presidential primary, a contest held in violation of party rules.

Asked whether he regrets that his campaign was pushing the story of racial divisiveness, Obama replied, "not only in hindsight, but going forward."

For her part, Clinton sidestepped when asked whether she would ban businessman Robert Johnson from a role in her campaign. Johnson made an evident reference to Obama's youthful drug use in a weekend appearance — although he denied that was his intent.

Still, asked whether Johnson's comments were inappropriate, she replied, "yes, they were."

The Michigan primary was an election in name only, where Clinton was the only major candidate entered. She faced competition principally from the "uncommitted" line on the ballot, an option that some supporters of Edwards and Obama advocated to embarrass the former first lady.

Returns from nearly 25 percent of the state's precincts showed her with 61 percent of the vote, and uncommitted gaining about a third.

The debate was held four days before Saturday's caucuses in Nevada, the next official event in a wide open race for the party's presidential nomination.

Obama won the leadoff Iowa caucuses less than two weeks ago, but Clinton rebounded with an upset victory in the New Hampshire primary. Edwards has yet to win a contest.

Pre-caucus polls in Nevada make it a close race among the three, an event spiced by a lawsuit filed by several Clinton supporters hoping to challenge the ground rules.

Their objective was to prevent several caucuses along the Las Vegas Strip, where thousands of Culinary Workers Union employees — many of them Hispanic or black — hold jobs.

The rules were approved in May, when Clinton was the overwhelming national front-runner in the race. But the union voted to endorse Obama last week, and the lawsuit followed.