Bill Richardson, the nation's only Hispanic governor, backed Barack Obama for president Friday in Oregon, answering speculation over one of the most heavily sought endorsements this primary season.

The New Mexico governor, who dropped out of the Democratic race for president in January, in his endorsement showed great admiration for Obama's speech on race delivered Tuesday in Philadelphia.

"Senator Obama reminded us that cynicism is not realism and that hope is not folly," Richardson said Friday. "He appealed to the best in us ... his words are one of a courageous, thoughtful leader who understands that a house divided against itself cannot stand."

Obama gave the Tuesday speech in part to respond to controversy surrounding his long-time pastor Jeremiah Wright Jr.

Richardson said Obama called on America to move past racial divisions. Calling him a "once-in-a-lifetime leader," Richardson also praised the Illinois senator for his longstanding opposition to the Iraq war.

The governor's endorsement comes as Obama leads among delegates selected at primaries and caucuses but with national public opinion polling showing Hillary Clinton pulling ahead of him amid controversy over statements by his former pastor.

Richardson had been relentlessly wooed by Obama and Clinton for his endorsement. As a Democratic superdelegate, the governor plays a part in the tight race for nominating votes and could bring other superdelegates to Obama's side. He also has been mentioned as a potential running mate for either candidate.

His support could help serve as a counterweight for Obama to Clinton's widespread popularity among Hispanic voters.

Clinton has been the favorite of Hispanics in primaries and caucuses, according to exit polls. She won the New Mexico caucus in early February with a nearly 2-to-1 advantage among Hispanics.

Citing Clinton's victory there, senior strategist Mark Penn said, "Perhaps the time when (Richardson) could have been most effective has long since past."

Clinton spokesman Jay Carson issued a statement saying the campaign respects Richardson, "but both of us have many great endorsers and the voters, not endorsers, will decide this election, and there are still millions of voters in upcoming contests who want to have their voices heard."

No primaries are scheduled until Pennsylvania's on April 22, a gap in time Obama hopes to use for such announcements to assert that he is the front-runner for the nomination.

Richardson backed Obama despite his ties to Clinton and her husband, the former president. He served as ambassador to the U.N. and as secretary of the Energy Department during the Clinton administration. Last month, Richardson and former President Clinton watched the Super Bowl together at the governor's residence in Santa Fe.

Richardson praised Hillary Clinton as a "distinguished leader with vast experience." But the governor said Obama "will be a historic and great president, who can bring us the change we so desperately need by bringing us together as a nation here at home and with our allies abroad."

Richardson was a roving diplomatic troubleshooter when he was a congressman from New Mexico, negotiating the release of U.S. hostages in several countries and meeting with a rogue's gallery of U.S. adversaries, including Saddam Hussein and Fidel Castro.

"There is no doubt in my mind that Barack Obama has the judgment and courage we need in a commander in chief when our nation's security is on the line. He showed this judgment by opposing the Iraq war from the start, and he has show it during this campaign by standing up for a new era in American leadership internationally," Richardson said.

Obama said he was "deeply honored" to have Richardson's support.

"Whether it's fighting to end the Iraq war or stop the genocide in Darfur or prevent nuclear weapons from falling into the hands of terrorists, Gov. Richardson has been a powerful voice on issues of global security, peace and justice, earning five Nobel Peace Prize nominations," Obama said in a statement.

The Associated Press contributed to this report.