A head to head comparison of the Minnesota 2020 Caucus Primary gives us an idea of the break down of the voters.
Biden got 33% ( 287,553) of the vote to beat Donald Trump who got 16% (137,275 votes) and Bernie Sanders who got 26% (222,431 votes).
In 2020 Minnesota Caucuses, Donald Trump seem to have had an upper hand comparing patronage for his movement to that of Biden and Sanders.
Bernie Sanders vs Joe Biden
Joe Biden vs Donald Trump
Donald Trump vs Joe Biden
In a head to head match up on just the total number of votes, Joe Biden (56%) beats Bernie Sanders (44%). Bernie Sanders (62%) beats Donald Trump (38%). Joe Biden (68%) beats Donald Trump (32%).
These 10 counties play an important role in these primary elections. If a candidate, can get a sizable majority makes it almost irrelevant from the smaller counties, unless like Donald Trump, you win a massive number of counties with a decent margin.
Joe Biden got more votes from the top 10 vote size counties. This gave him an upper hand over Bernie Sanders and Donald Trump in the state of Minnesota.