The decline in Barack Obama's popularity since July has been the steepest of any president at the same stage of his first term for more than 50 years.
By Toby Harnden in Washington
Gallup recorded an average daily approval rating of 53 per cent for Mr Obama for the third quarter of the year, a sharp drop from the 62 per cent he recorded from April.
His current approval rating – hovering just above the level that would make re-election an uphill struggle – is close to the bottom for newly-elected president. Mr Obama entered the White House with a soaring 78 per cent approval rating.
The bad polling news came as Mr Obama returned to the campaign trail to prevent his Democratic party losing two governorships next month in states in which he defeated Senator John McCain in last November's election.
Jeffrey Jones of Gallup explained: "The dominant political focus for Obama in the third quarter was the push for health care reform, including his nationally televised address to Congress in early September.
"Obama hoped that Congress would vote on health care legislation before its August recess, but that goal was missed, and some members of Congress faced angry constituents at town hall meetings to discuss health care reform. Meanwhile, unemployment continued to climb near 10 per cent."
Governor Jon Corzine of New Jersey is in severe danger of defeat while Democrats are fast losing hope that Creigh Deeds can beat his Republican opponent in Virginia. Twin Democratic losses would be a major blow to Mr Obama's prestige.
Campaigning for Mr Corzine in Hackensack on Wednesday night, Mr Obama delivered a plea that almost seemed as much for himself as the local candidate: "I'm here today to urge you to cast aside the cynics and the sceptics, and prove to all Americans that leaders who do what's right and who do what's hard will be rewarded and not rejected."
Mr Corzine, a former Goldman Sachs executive and multi-millionaire, is currently running even in New Jersey, which is normally comfortably Democratic, while Mr Deeds is trailing badly in Virginia, a swing state that was key to Mr Obama's 2008 victory.
Mr Obama is also facing widespread criticism for his drawn-out decision-making process over what to do next in Afghanistan.
Republicans sense Mr Obama is in a vulnerable position and this week saw the return to the public stage of his perhaps most vehement opponent – Vice-President Dick Cheney.
In a blistering speech on Wednesday night, he accused Mr Obama of failing to give Americans troops on the ground a clear mission or defined goals and of being seemingly "afraid to make a decision" about Afghanistan "The White House must stop dithering while America's armed forces are in danger," Cheney said at the Center for Security Policy in Washington.
"Make no mistake, signals of indecision out of Washington hurt our allies and embolden our adversaries."
He hit out at Obama aides who suggested that the Bush administration had failed to weigh up conditions in Afghanistan properly before committing troops.
"Now they seem to be pulling back and blaming others for their failure to implement the strategy they embraced. It's time for President Obama to do what it takes to win a war he has repeatedly and rightly called a war of necessity."
Click to view image: '6626c6800681-milliobamani.jpg'
|Liveleak on Facebook|