39% sounds about right. I don't imagine it will go below 35%. I think there are fewer low-information voters than most people think but there are far more who are in willful denial.
Lower than Bush's approval this time in his Presidency... and considering the different treatment from the media, that says a lot.
http://www.gallup.com/poll/116500/presidential-approval-ratings-george-bush.aspx
It ought to be in the teens, but this is what America is like now. If Obama ran for a third term today, he would win again.