Per Marquette Poll: Early voters going for Obama 56-36 in WI
Early voting
Ten percent of likely voters said they have already voted, with a week left for early voting at the end of interviewing. This is consistent with the Wisconsin Government Accountability Boards estimate that about 20 percent of votes will be cast early. Early voters gave Obama 56 percent to 36 percent for Romney and 1 percent for third party candidates. Seven percent of early voters declined to say for whom they voted. In the Senate race Baldwin received 52 percent to Thompsons 36 percent among early voters in the poll, with 1 percent for third party candidates. Ten percent declined to say whom they supported.
https://law.marquette.edu/poll/
And now it isn't enough to be a 'likely voter' when likely voters break big for Obama:
Turnout and get out the vote efforts
Turnout could play a big role in the election, according to Poll Director Charles Franklin. Among all likely voters Obama leads by 8 points, but among those who both are likely to vote and also follow politics most closely, the margin is just two points, 48-46 percent. It works to Obamas advantage if the less interested voters turn out, while it improves Romneys chances if they stay home. This shows how get out the vote efforts of both parties can affect the results. The Senate race similarly tightens among likely voters who follow politics most closely, narrowing to 47 percent for Baldwin to 46 percent for Thompson.