Washington - Confidence in President Barack Obama has dropped below 50% to its lowest level in 19 months as Americans worry over broad government surveillance and other controversies, a poll showed Monday.
The tumbling approval numbers come as the White House faces criticism about a domestic program that gathers data on millions of Americans, the US tax agency's targeting of conservative groups which applied for tax-exempt status, and secret collection of journalists' phone records.
Obama's approval rating has now dropped to 45%, an eight-point slide since mid-May, according to CNN which conducted the survey.
Some 54% of the public say they disapprove of how the president is handling his job, marking the first time since November 2011 that a CNN poll showed a majority of Americans with a negative view of Obama.
It shows that for the first time in Obama's presidency, half of Americans do not believe he is honest and trustworthy.
"The drop in Obama's support is fueled by a dramatic 17-point decline over the past month among people under 30, who, along with black Americans, had been the most loyal part of the Obama coalition," CNN polling director Keating Holland said.
Fifty-one percent of respondents say that the existing National Security Agency program that scoops up a billion phone records per day - a programme leaked by a former defense contractor - is appropriate as part of counter-terrorism efforts.
But 43% say Obama has crossed the line in restricting civil liberties in order to fight terrorism, according to the telephone poll of 1 014 people 11-13 June.
"It is clear that revelations about NSA surveillance programs have damaged Obama's standing with the public, although older controversies like the IRS matter may have begun to take their toll as well," Holland said.
Obama opponents have seized on an inspector's damning May report which concluded that Internal Revenue Service agents inappropriately targeted tea party groups, to highlight abuse of power by the administration.
They also pointed to the White House's handling of a deadly attack on the US mission in Benghazi, Libya last 11 September, and revelations that the Justice Department ordered the seizure of reporters' phone records as part of a leak probe.
Number two House Republican Eric Cantor told CNN that the poll sends a "troubling" message to Obama in that the public is witnessing "a government that has abused its power, and, frankly, has lost focus on the issue that most Americans care about, which is getting people back to work".
But he held fire on the surveillance programmes themselves, saying he believed they strike a balance between civil liberties and national security.