Democratic presidential rivals Hillary Rodham Clinton and Barack Obama stepped back from a controversy over race last night, agreeing that a prolonged clash over civil rights could harm their party's overall drive to win the White House.

The two leading Democratic contenders shifted course as Republicans pointed toward today's pivotal primary in Michigan, where Mitt Romney and John McCain both pledged to lead a revival for a state and an auto industry ravaged by recession.

Obama was the first to suggest a cooling of the rhetoric on race, calling reporters together to say he didn't want the campaign "to degenerate into so much tit-for-tat, back-and-forth that we lose sight of why all of us are doing this."

Referring to Clinton and former Sen. John Edwards, he said that while they may have disagreements, "we share the same goals. We're all Democrats, we all believe in civil rights, we all believe in equal rights."

Clinton's campaign issued a statement in the same vein about an hour after Obama spoke, saying it was time to seek common ground. "And in that spirit, let's come together, because I want more than anything else to ensure that our family stays together on the front lines of the struggle to expand rights for all Americans," she said.

For all the maneuvering, Democrats are without a contested election today.

That was in contrast to the Republican campaign, where McCain and Romney battled in a Michigan primary that neither could afford to lose.

"I will not rest until Michigan is back," said Romney, a native son who jabbed at his rival for saying many jobs among the thousands lost will never return.

"We will create new jobs," insisted McCain, who also favors improvements in federal programs for laid-off workers. "We have the innovation, the talent, the knowledge and the ability ... to regain Michigan's position as the best in the world."

Polls showed McCain and Romney in a close race, with former Arkansas Gov. Mike Huckabee running third.

Of the three, Romney is most in need of a victory as he looks to restore at least some of the luster lost with defeats in the Iowa caucuses and New Hampshire primary. Several associates have suggested the former Massachusetts governor may quit the race unless he prevails.