You have to factor in the exit poll Barrett bias. The exits are great news for Romney. If he is only down by 6 in the exits and those exits have a 12 point Barrett bias, that means Romney is actually up by about 6. This extrapolation may be off by a point or so, but Wisco is a toss-up, maybe lean very slightly Romney.
There is no exit poll Barrett bias, absentee ballots could not be "exit polled".
Exit polls did not make that much of a difference. There was clearly a bias towards Barrett, considering it said he was tied and he lost by 7-8 points. Wasn't even that close - around same margin as McCain and Obama.
It was about as close to a tie as it was to McCain/Obama. Obama won by about 14 points.