U.S. President George W. Bush's approval rating has sunk to 28 percent, an all-time low during his presidency, the latest Newsweek magazine poll released on Saturday showed.

The approval rating was also the lowest for a U.S. president in a generation, according to the poll, which was conducted with 1,001 adults on Wednesday and Thursday.

Nearly two out of three Americans - 62 percent - believed Bush's recent actions in Iraq showed he was "stubborn and unwilling to admit his mistakes," compared to 30 percent who said his actions demonstrated that he was "willing to take political risks to do what's right," the survey found.

The low rating seemed to be casting a dark shadow over the Republican Party's chances for victory in the 2008 presidential elections, as the poll found each of the leading Democratic presidential hopefuls beating the Republican frontrunners in head-to-head matchups.

If the elections were held now, Democratic Senator Barack Obama of Illinois would best former New York mayor Rudy Giuliani 50 percent to 43 percent among registered voters, beat Republican Senator John McCain of Arizona 52 percent to 39 percent, and defeat former Massachusetts governor Mitt Romney 58 percent to 29 percent.

Senator Hillary Clinton of New York would win the elections 49 percent to 46 percent against Giuliani, 50 to 44 against McCain, and 57 to 35 against Romney.

Another leading Democratic candidate, a former senator of North Carolina, would defeat Giuliani by six percentage points, McCain by 10 and Romney by 37 points.

The Newsweek poll was conducted by Princeton Survey Research Associates International, and had a margin of error at plus or minus four percentage points.

Source: Xinhua