Poll: Trump's approval rating plummets in one of the key states that won him the election

President Donald Trump pulled off a surprising victory in Wisconsin during the 2016 election, helping to propel him to an electoral college victory over Hillary Clinton -- but a new poll found that voters have soured on him since election day.

Six month into his administration, more than half of voters in the Badger State disapprove of Trump's job performance, according to a new poll released this week.

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The Marquette University Law School poll of registered voters finds only 41 percent approve of Trump while 51 percent disapprove of him.

While not an overwhelmingly Democratic-leaning state, Wisconsin had been won by the Democratic presidential candidate in every election going back to 1984 until Trump's surprising win in 2016. He won the state by a margin of less than 25,000 votes -- less than one percentage point.

For most of the campaign, polls showed Trump losing to Hillary Clinton in the state.

Trump's disapproval has worsened since a March version of the poll, which showed 47 percent disapproved of his job performance.

The survey revealed a stark partisan divide as well. Among Democrats, 95 percent disapproved of Trump's job performance while 85 percent of Republicans approved.

Voters are split over Gov. Scott Walker, a fellow Republican who briefly launched his own run for the White House in 2016. The poll showed that 48 percent approve of his job as governor of Wisconsin -- an increase of three point since March -- while another 48 percent disapprove.