The poll is a big swing from previous results from the survey, which had Romney within 1 point in mid-October. It's unlikely the race has swung that dramatically in the two weeks since the last poll was released, as national polling has shown a relatively stable race during that period.

Rep. Tammy BaldwinTammy BaldwinSenate approves Trump's Agriculture chief Lawmakers talk climate for Earth Day, Science March Trump says he supports Dem ‘Buy America’ bill MORE (D-Wis.) leads former Wisconsin Gov. Tommy Thompson (R) by 4 points in the state's hard-fought Senate race, according to the poll. She's up 47 percent to 43 percent. Other recent polls have shown the race within the margin of error.

There has been little recent public polling of the state, though a poll from the conservative Rasmussen Reports released earlier this week had the race tied. Two nonpartisan, mid-October polls had Obama leading by 2 and 6 points.

The poll of 1,243 likely voters was conducted from Oct. 25-28 and has a margin of error of plus or minus 2.8 percentage points.