WASHINGTON - U.S. President Barack Obama's approval ratings are keeping pace with the improving U.S. economy, helped as well by the growing turmoil in the Republican contest for the nomination to challenge him in November.

While the Republicans fiercely battle one another, the president was expected to collect more than $8 million from fundraising events that will take him from Los Angeles and San Francisco on Thursday to the Seattle area on Friday.

During a fundraising breakfast in a beach side community outside Los Angeles, Obama told about 125 donors that his 2008 campaign had brought with it "a sense of possibility" for moving the country in a new direction. "We've begun that process but the journey is not complete," the president said.

Obama took in more than $220 million in campaign contributions last year and is bolstering that funding base as the Republican presidential contest remains unsettled.

Obama was in California after a stop in Wisconsin a day earlier in which he hailed a company's decision to move some operations back to the United States from abroad, reversing the trend of so-called outsourcing that has badly damaged the United States' manufacturing sector.

At the luxurious home of a Hollywood soap opera producer Wednesday night, the president urged Democrats to mobilize, telling supporters that the 2012 election "is not going to be easier this time. It's going to be harder this time."

"People out there are hurting and they need us to do more," Obama said on a star-studded night that included a performance by the Foo Fighters and appearances by other celebrities.

Obama later told donors at an intimate dinner -- including actors George Clooney and Jim Belushi -- that he understood that some of his supporters remain frustrated that the war in Afghanistan has yet to end and the U.S. military-run prison at Guantanamo Bay, Cuba, remains open.

California has been a mainstay of Democratic party fundraising -- and a reliably Democratic-voting state -- and Obama's campaign expected to collect millions from six events in Los Angeles and San Francisco over two days.

Polls showed the president in a far better position than at any time since he ordered the Special Forces operation that killed al-Qaida leader Osama bin Laden last May.

But the president's approval remains closely tied to the economy, which shows signs of accelerated improvement after a painfully slow recovery from the 2007-2009 Great Recession but remains fragile. It could easily be knocked off course by further financial tumult in Europe, a spike in oil prices -- especially if Israel bombs Iranian nuclear facilities -- or an increase in the U.S. unemployment rate.

The Gallup polling organization shows Obama has pulled out of a downward slide that took him into dangerously low territory, with just 38 per cent approval and 55 per cent disapproval late last August. The organization's latest daily tracking poll showed the president with equal approval and disapproval ratings of 45 per cent Wednesday.

A New York Times/CBS poll released on Tuesday puts him in an even better place, with 50 per cent approval, although perceptions of his handling of the economy are still in negative territory, with just 44 per cent approving and 50 per cent not.

Obama seems certain to benefit from a deal reached late Wednesday in Congress to extend a payroll tax cut and extra jobless benefits through 2012. A bipartisan deal would mark a clear victory for Obama, who made the payroll tax cut the keystone jobs creation plan outlined in September.

Still unknown, however, is how voters will react when the fractious Republican fight ends with the nomination of a candidate at the party's national convention in late August.

Obama doesn't appear to be as strong in the so-called swing states -- those that shift between support for Democrats and Republicans from election to election -- as he was when he easily defeated Sen. John McCain in 2008.

A poll by the Pew Research Center for the People & the Press gives Obama a 10-point margin when measured against either presumed front-runner Mitt Romney or rising challenger Rick Santorum. The Times/CBS survey gives Obama a six-point, 48-42 per cent advantage over Romney and seven points over Santorum, 49-41.