Barack Obama leads the entire Republican field in both Wisconsin and Iowa, two states that were hotly contested in 2000 and 2004 but that he won easily in 2008.
Obama is not popular in either state. In Iowa just 45% of voters approve of him to 48% who disapprove. Independents split against him 43/47 and only 79% of Democrats think he's doing a good job while 87% of Republicans give him bad marks. It's a pretty similar story in Wisconsin. There an equal 45% of voters approve of him with his disapproval number standing at 51%. Independents go against him 40/52 and 94% of Republicans disapprove of him to 86% of Democrats who rate him positively.
Obama's not running for reelection in a vacuum though and given the GOP alternatives he still leads in both of these states. In Wisconsin he's clearly weaker at this point than in 2008, when he won the state by 14 points. He leads Mitt Romney only 47-42. And while he does have double digit advantages over the rest of the Republican field- 10 over Rick Perry at 50-40, 12 over Michele Bachmann and Sarah Palin at 51-39 and 52-40 respectively, and 14 over Herman Cain at 50-36- for the most part he's not matching his margin of victory from last time.
It's a different story in Iowa though and that may bode well for Obama in terms of what happens when voters get a lot of exposure to the Republican candidates. There he actually exceeds his 2008 margin of victory against the entire GOP field- he's up 10 on Romney at 49-39, 13 on Perry at 51-38, 17 on Bachmann at 51-34, 18 on Cain at 51-33, and 21 on Palin at 54-33.
Iowa's a closely divided state in terms of its partisan loyalties, meaning it's one of those places where independents really do make the difference. Romney's favorability with them is 27/55. Perry's is 23/52. Bachmann's is 22/60. And Obama has leads of 13, 17, and 17 points respectively with independents over the three of them. What those folks have to say to make the Republican base happy doesn't look like it will serve them well heading toward November. It's just one poll and one state but it points to the possibility that Obama can win with a 45% approval rating because the GOP field is so bad.
One last point- with Romney doing 5 points better than Perry against Obama in Wisconsin and 3 points in Iowa it's another data point showing that the Perry surge is good news for Obama's reelection prospects.
Full results here