A head to head comparison of the Iowa 2020 General Election gives us an idea of the break down of the voters.
Joni Ernst received 865k (53.4 %) votes, beating Theresa Greenfield who gained 754.9k (46.6 %) by 110.1k votes in Iowa.
Theresa Greenfield won 8 counties out of the 99 counties that make up Iowa. The record shows that Joni Ernst won 91 counties.
During the 2020 general elections, over 2M total number of votes were cast. Joni Ernst got 864,997 (865k) over Theresa Greenfield 754,859 (755k). He won the popular vote by 864,997 (865k). His victory in the State of Iowa (with 864,997 votes) represents 50.0% of his popular vote victory.
Top 15 Counties in General Elections
All Candidates (Senate General Elections)
These 15 counties play an important role in these Primary elections. If a candidate, can get a sizable majority in the largest counties (Polk, Linn and Scott), it becomes very difficult to win majorities in the smaller counties without voter outreach and increased voter participation in them.
Top 15 Counties Comparison in General Elections
Polk, Linn and Johnson, three of the larger counties voted in favor of Theresa Greenfield, giving him a 66k vote advantage.