A head to head comparison of the Arizona 2020 Primary gives us an idea of the break down of the voters.
Biden received 57% (268K votes) beating Sanders who had 42% (200k votes) and Gabbard who had 1% (3k votes). There was no Presidential Primary for the Republican Party in the State of Arizona, thus there are no results for President Trump at the Primary level.
Biden won 13 out of the 15 counties in the state of Arizona while Sanders won the remaining 2 counties. There was no Presidential Primary Elections for the Republican Party.
These 10 counties play an important role in these primary elections. Winning Maricopa county is essential to winning the primary election in the state of Arizona. Since there are only 15 total counties, these top 10 are necessary to win.
Bernie Sanders vs Joe Biden
In a head to head match up on just the total number of votes, Bernie Sanders (57%) beats Joe Biden (43%).
Bernie Sanders
Joe Biden
Joe Biden won the largest percentage of votes in Maricopa county, providing him a large number of votes that boosted his potential to win. Winning the other 12 counties secured him the victory in the state of Arizona. The small counties won by Bernie Sanders were not enough to overcome the voters won by Joe Biden in the 13 counties he won. There was no Presidential Primary for the Republican Party in the State of New York, thus there are no results for President Trump at the Primary level.
Related References: 2016 Arizona General Election Story, 2016 Arizona Primary Election Story