The ABC News-Washington Post survey shows President Obama ahead 51 percent to 45 percent among registered voters, and 52 percent to 43 percent among all Americans.

　　The poll, conducted last week among a random sample of 1,000 adults, shows half of those surveyed approve of the president's job performance and believe he deserves a second term.

　　In a televised interview Sunday, President Obama said he deserves to be re-elected, citing new figures that indicate the economy is adding jobs. He told NBC the economy is doing much better than when he took office three years ago, but that, "we are not done."

　　The president noted a report that said the unemployment rate fell in January for the fifth month in a row, with nearly 250,000 jobs added. In 2009, he said, the economy was losing three times that many jobs per month.

　　But the Republican presidential hopefuls say the economy is not recovering fast enough and Obama's policies have been ineffective.

　　The four Republican candidates are campaigning in the states of Minnesota and Colorado, which hold caucuses Tuesday.

　　Former Massachusetts governor Romney appears poised to win Colorado caucuses Tuesday. But polls in Minnesota suggest any one of four candidates could take first place, with former senator Rick Santorum in the lead.

　　Opinion surveys in both states show former House speaker Newt Gingrich has lost significant support.

　　Gingrich had been considered Romney's closest rival for the nomination, and in December held a commanding lead in Colorado polls. He is now in third place in that state.

　　Public Policy Polling, which conducted the latest surveys, says Santorum has been helped because no other candidates have been attacking him. Santorum is also polling well in Missouri, according to Public Policy Polling's latest survey there last week.

　　Gingrich is vowing to fight all the way to the nominating convention, being held in Tampa, Florida, in August.

　　Representative Ron Paul also remains in the race, but is trailing the other three candidates.