A head to head comparison of the Iowa 2016 General Election gives us an idea of the break down of the voters.
Charles E. Grassley received 926k (60.2 %) votes, beating Patty Judge who gained 549.5k (35.7 %) by 376.5k votes in Iowa.
Patty Judge won 1 counties out of the 99 counties that make up Iowa. The record shows that Charles E. Grassley won 98 counties.
During the 2016 general elections, over 2M total number of votes were cast. Charles Aldrich got 41,794 (42k) over Charles E. Grassley 926,007 (926k). He won the popular vote by 41,794 (42k). His victory in the State of Iowa (with 41,794 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
Charles E. Grassley
Polk, Linn and Scott, three of the larger counties voted in favor of Charles E. Grassley, giving him a 37k vote advantage.