Though Obama's showing is weaker than his position in 2008, the PPP poll found 50 percent of voters would support him, compared with 44 percent for presumptive Republican presidential nominee Mitt Romney.
Only 47 percent of the 1,057 Wisconsin voters surveyed Thursday through Sunday said they think Obama is doing a good job compared with 48 percent who said they disapproved.
Only 41 percent said they think favorably of Romney, compared with 50 percent who said they have a negative opinion.
"Barack Obama's the clear favorite to win Wisconsin," said Dean Debnam, president of Public Policy Polling. "But it looks like it will be a much closer race than his 14-point victory in 2008."
The survey had an error rate of 3.3 percentage points.