A head to head comparison of the Wisconsin 2016 Primary gives us an idea of the break down of the voters.
Bernie Sanders received 27% (567K votes) beating both Hillary Clinton by 6% (432K votes) and Donald Trump by 9% (386K votes) in the overall count of votes in Wisconsin.
Bernie Sanders won 25 of the counties. Donald Trump won more counties, but the counties he won did not have as many voters and the counties Bernie Sanders won. Hillary Clinton won only 1 county in this 4-way match up.
Bernie Sanders vs Clinton
Hillary Clinton vs Donald Trump
Donald Trump vs Bernie Sanders
In a head to head match up on just the total number of votes, Hillary Clinton (43%) lost to Bernie Sanders (57%). Hillary Clinton vs Donald Trump, she wins by 6%. Bernie Sanders Beats Donald Trump by 20%.
These 10 counties play an important role in these primary elections. If a candidate can get a sizable majority or even a high minority (like Bernie Sanders) in the biggest counties (Milwaukee, Dane, and Waukesha) they can win a majority of total state votes. Donald Trump won in more counties than Bernie Sanders, but lost to him by 9%.
Bernie Sanders top three counties secured him more votes than the top three counties of Donald Trump or Hillary Clinton. This helped Bernie Sanders win the vote in the state of Wisconsin.
Related References: 2016 Wisconsin General Election Story, 2020 Wisconsin Primary Election Story, 2020 Wisconsin General Election Story, Wisconsin Early Voting Absentee Data on Nov 1st, 2020 as compared to 2000 through 2020 General Election Votes