The poll indicated public approval ratings fell to the 50 percent mark, down 5 percentage points from before he was sworn in for a second term in January.
In December, just after he won a second term, Obama had an 18-percentage-point lead over congressional Republicans on the question of who was trusted more to deal with the economy. Now, Obama's advantage has shrunk 4 points, 44 percent to 40 percent, the Post said.
Nearly two weeks into the automatic across-the-board budget cuts, known as the sequester, a slim majority of Americans said they disapprove of the reductions, results indicated. Nearly three-quarters said they haven't felt an impact on their lives and about half said they expect their family finances to take a hit if the cuts are allowed to remain in effect.
Results also showed a majority said it expects the sequester eventually will hurt the economy, the military and the government's ability to provide basic services. Sixty-eight percent said they would like the two sides to reach a deal to stop the cuts.
Forty-seven percent said they thought congressional Republicans were responsible for the sequester and 33 percent blamed Obama.
Public approval of Congress remained low, with 16 percent approving of its performance and 80 percent disapproving, results indicated.
Results are based on a nationwide sampling of 1,001 adults conducted Thursday through Sunday. The margin of error is 3.5 percentage points.