Obama: 50%
McCain: 37%

Some perspective from WisPolitics:

Wisconsin was a key battleground in the presidential contests of 2000 and 2004 and saw extraordinarily tight contests in both years. Al Gore beat George W. Bush by 5,708 votes (0.2 percent) in 2000, and John Kerry bested Bush by 11,384 votes in 2004 (0.38 percent). Goldstein points out, “In both 2000 and 2004, party attachments in the state were virtually identical with equal numbers of voters identifying with the Democrats and the GOP. One of the striking results in this poll and consistent with other survey work I have done in the state, the Democrats now enjoy a major advantage in party identification.” In the study, 38 percent of probable voters identified with the Democrats and 24 percent with Republicans.

Obama has very strong favorable ratings with 64 percent of Wisconsin probable voters saying they have a favorable opinion and 32 percent having an unfavorable opinion. McCain also has relatively strong favorables, too, at 53 percent to 44 percent. Obama is seen as the candidate to bring about change (70 percent to McCain’s 42 percent) while McCain is seen as the experienced candidate (84 percent to Obama’s 43 percent). Still, as the evidence shows, McCain faces a stiff headwind in Wisconsin.

Of note, this is the very first poll from this University of Wisconsin’s Department of Political Science, so we may want to take this with a grain of salt.

Still, Obama did exceedingly well here during the primaries and if a few other polls come out and paint it solidly blue, he may not need to spend much money in the fall.

Politics Poll: Obama Leads McCain By 13 In Wisconsin