Barack Obama would win Iowa again if he had to stand for reelection today, although Mike Huckabee and Mitt Romney would both give him a more competitive contest than John McCain did in 2008.
Obama is reasonably popular in the state with 50% of voters approving of his job performance to 43% who disapprove. Democrats (87%) are pretty universal in their approval of him while Republicans (82%) are pretty unanimous in their disapproval. Breaking the tie is his numbers with independents, 49% of whom give him good marks to 40% who are unhappy with the job he's doing.
Obama won the state by 9 points in 2008. Against Huckabee he leads by only 4 points, 47-43, and against Romney it's just a 6 point advantage, 47-41. He would win in more dominant fashion against Newt Gingrich who he leads by 13 points at 51-38 and against Sarah Palin who he expands the gap to 16 points against at 53-37.
http://publicpolicypolling.blogspot.com/