The survey of 923 adults by CNN and the ORC International polling organisation found that 45 per cent of respondents disapprove of Obama's job performance.
In early April, the same poll gave the president a 51 per cent approval rating, showing that Obama is holding steady despite a brutal week in which the White House attempted to control damage from three simultaneous scandals which threatened to derail his agenda.
Republicans have used the affairs to accuse the Obama administration of being guilty of a massive abuse of power, which the White House denies.
The polls showed that most Americans believe the scandals are either "somewhat important" or "very important," but for the time being were giving Obama the benefit of the doubt.