Washington ? A new national survey shows that barely half the country approves of President Bush’s job performance, his lowest approval rating since taking office.

The new Gallup/CNN/ USA Today poll also finds that retired Gen. Wesley Clark, who announced his candidacy last week, would narrowly defeat Bush in a head-to-head match-up if the election were held now. The survey also found that other Democratic contenders would run no worse than even with Bush, if the poll’s margin of error of 3.5 percentage points is taken into account.

The poll, completed Sunday and released Monday, shows a total of 50 percent of Americans surveyed gave Bush positive marks for his performance as president; 47 percent disapproved. That was 1 point below Bush’s previous low: a 51 percent approval rating in a Gallup survey completed the day before the Sept. 11 attacks.