A head to head comparison of the 2020 Primary gives us an idea of the break down of the voters.
Bernie Sanders received 7,682 (57%) votes to beat Joe Biden, who received 5,742 (43%) votes and Donald Trump, who received no votes. There was no Presidential Primary for the Republican Party in the State of North Dakota, thus there are no results for President Trump at the Primary level.
In the Primary, Sanders won 32 counties in the 3-way match up. Biden trailed behind Sanders winning 15 counties with Trump winning nothing in North Dakota Primary. There was no Presidential Primary Elections for the Republican Party.
Bernie Sanders vs Joe Biden
In the head to head match ups, Sanders (57%) beat Biden (43%).
These 10 Legislative Districts play an important role in these primary elections. Since many of the Legislative Districts have a similar amount of voters, winning the larger ones does not guarantee winning at the State. It is possible to catch up from the smaller ones.
Sander's steady win at most Legislative Districts gave him the upper hand in the State of North Dakota. There was no Presidential Primary for the Republican Party in the State of North Dakota, thus there are no results for President Trump at the Primary level.
Related References: 2016 North Dakota General Election Story, 2016 North Dakota Primary Election Story