Clinton also leads by a wide margin over Sen. Marco Rubio, R-Fla., who, like Clinton is considered a possible successor to Obama in 2016, the ABC News/Washington Post poll released Wednesday indicated.
Six in 10 Americans said they view Clinton favorably, down 6 percentage points from her career high in January. Obama is seen favorably by 53 percent, down 7 percentage points from January.
Rubio, a member of the Senate's bipartisan "Gang of Eight" shepherding sweeping immigration reform legislation through the upper chamber, is less known on the national stage, the poll indicated. Half of Americans express no opinion at all while the rest was divided evenly, the poll said.
Clinton's popularity since January dropped among Republicans and "somewhat" among conservative Americans, results indicated. The former first lady also lost ground among whites, seniors and college graduates.
Obama's favorability fell among liberals, independents, those without a college degrees, non-whites and people with household incomes less than $50,000 a year.
Results are based on a nationwide telephone survey of 1,010 adults conducted June 19-23. The margin of error is 3.5 percentage points.
Notable deaths of 2014 [PHOTOS]
Texas oil tycoon Nelson Bunker Hunt dead at 88