Former Vice President Joe BidenJoe BidenCapitol fencing starts coming down after 'Justice for J6' rally Senate parliamentarian nixes Democrats' immigration plan Biden pushes back at Democrats on taxes MORE leads President TrumpDonald TrumpCapitol fencing starts coming down after 'Justice for J6' rally Netanyahu suggests Biden fell asleep in meeting with Israeli PM Aides try to keep Biden away from unscripted events or long interviews, book claims MORE by nine points among Wisconsin voters while Sen. Bernie SandersBernie SandersManchin suggests pausing talks on .5 trillion package until 2022: report Yarmuth and Clyburn suggest .5T package may be slimmed Sanders calls deadly Afghan drone strike 'unacceptable' MORE (I-Vt.) leads by four points, according to a new Marquette University Law poll released on Wednesday.
Fifty-one percent of voters in the state said they supported Biden, while only 42 percent voiced support for Trump, according to the survey.
The same survey found that Sanders led Trump by four points, or 48 percent to 44 percent.
Meanwhile, the president is neck-and-neck with Sen. Elizabeth WarrenElizabeth WarrenThe Trojan Horse of protectionism Federal Reserve officials' stock trading sparks ethics review Manchin keeps Washington guessing on what he wants MORE (D-Mass.), with both receiving 45 percent support.
Trump was also tied with Sen. Kamala HarrisKamala HarrisRepublicans caught in California's recall trap Harris facilitates coin toss at Howard University football game Far-right rally draws small crowd, large police presence at Capitol MORE (D-Calif.), with both coming in at 44 percent support.
Wisconsin will likely be a must-win state for Democrats in 2020 given that President Trump flipped the state from blue to red, helping propel him to his surprise victory in 2016.
Biden also led the Democratic primary field in Wisconsin, according to the poll, with 28 percent of those surveyed naming him as their first choice.
Sanders was the first choice of 20 percent of the same pool of respondents, while Warren was the first choice of 17 percent of respondents.
Sanders had won Wisconsin the 2016 Democratic primary race with 56 percent of the vote.
Meanwhile, the economy, likely a key electoral issue in 2020, elicited split views from voters in Wisconsin. Forty-nine percent of respondents said they approved of the president's handling of the economy, while 50 percent said they disapproved.
The Marquette University Law School poll was conducted from August 25-29, 2019 among 800 registered Wisconsin voters. The margin of error is plus or minus 3.9 percentage points. Among registered Democrats, Democratic-leaners, and independents, the margin of error is plus or minus 5.3 percentage points.