WASHINGTON (AFP) - President Barack Obama Wednesday brushed aside a sharp polls rebuke as he marked the first anniversary of his historic election saying his administration had saved the nation from economic ruin.

Just hours after rival Republicans gleefully ousted Democratic candidates in two key gubernatorial races, the White House dismissed suggestions that the results were a referendum on Obama and his policies.

A year to the day after Obama vowed before a tumultuous crowd in Chicago that change had come to America, Republicans were trumpeting Tuesday's victories in New Jersey and Virginia.

But Obama sought to remind a school audience in northern Wisconsin -- one of the states that swept him to victory over Senator John McCain on November 4, 2008 -- of the political landscape and economic outlook 12 months ago.

"One year ago, Americans all across this country went to the polls and cast ballots for the future they wanted to see," he told the crowd in the Madison school, which leapt to its feet in a standing ovation.

"Election day was a day of hope, it was a day of possibility, but it was also a sobering one because we knew even then that we faced an array of challenges that would test us as a country."

Republicans are hoping that Tuesday's victories could help turn the tide after their 2008 polls drubbing, as they look ahead to key mid-term elections in 2010.

"The Republican Party's overwhelming victory in Virginia is a blow to President Obama and the Democrat Party," Republican National Committee chairman Michael Steele said.

"It sends a clear signal that voters have had enough of the president's liberal agenda."

Obama was swept to power on a promise of change just as the United States was confronting its worst economic crisis in decades, and with US troops fighting two wars in Iraq and Afghanistan.

And he made it clear Wednesday that he would not be diverted from his program. "The work continues, but we are moving in the right direction," he pledged.

"And we are going to keep on fulfilling our obligation to do every single thing we possibly can to pull this economy out of the ditch and to make sure that people can find jobs that pay good wages. That's our top priority."

And White House spokesman Robert Gibbs said Republicans should not presume Tuesday's triumphs will translate into victory next year when all the House of Representatives and a third of the Senate is up for election.

"If you look at the exit polling, which is pretty clear on this, people went to the polls and voted on local issues, not to even register support for or opposition to the president," Gibbs said.

Obama's favored candidates lost the battle for the governor's mansion to Chris Christie in New Jersey and Bob McDonnell in Virginia even though he had campaigned for them.

Christie pulled off an upset victory over Jon Corzine with a 49-45 percent margin according to preliminary results, while McDonnell defeated Creigh Deeds by 59-41 percent in Virginia, with almost all precincts reporting.

But on Tuesday, for the first time in more than a century, a Democrat, Bill Owens, narrowly won a seat in a strong Republican congressional district of upstate New York.

Owens narrowly defeated conservative Republican challenger Doug Hoffman, who pulled back from behind in a surge by the conservative rightwing of the party which caused a more moderate Republican candidate to drop out.

Obama said his administration, sworn in after his inauguration on January 20, had had "two fundamental obligations."

"The first was to rescue the economy from imminent collapse. And while we still have a long way to go, we have made meaningful progress toward achieving that goal."

The actions taken by his administration such as implementing a 787-billion-dollar stimulus plan and introducing tax cuts "contributed to the first quarter of economic growth that we've had as a nation in over a year," he said.

The second obligation was "to tackle problems that had been festering, that had been kicked down the road year after year, decade after decade."

In other elections, New York Mayor Michael Bloomberg was re-elected to a third term in a surprisingly close contest after he poured millions of his own money into the campaign and changed the rules so he could stand again.

And in Maine, voters soundly rejected a law to allow same-sex marriage, in a blow to gay rights advocates hoping the northeastern US state would become the first in the country where voters directly approve gay unions.