Public Policy Polling:

Overall 49 percent of voters express approval of Obama’s work with 46 percent disapproving. He has the support of 83 percent of Democrats, 47 percent of independents, and 10 percent of Republicans.

Other results from PPP:

Hurting Obama’s overall reviews is that for the first time in our polling we find a majority of Americans opposed to his health care plan. 40% say they support it with 52% opposed, including 58% of independents.
“This is the first time President Obama’s approval rating has dropped below 50% in our polling,” said Dean Debnam, President of Public Policy Polling. “It does seem that the health care issue is hurting him some with independents who voted for him last year.”
The poll also found that 26% of Americans think ACORN stole the election for Obama last year, including 52% of Republicans. Overall 11% view the organization favorably while 53% have a negative opinion of it.

I would note that if you really sat down and asked Republicans about their views, less than 52 percent would say that ACORN is responsible for the 6-percentage-point, 9 million-or-so-vote margin in Obama’s election. I suspect that answer is akin to, “they’re all a bunch of crooks, and I wouldn’t put anything past them.”