Tom Harkin won with 54.2% of the vote (554,278 votes), ahead of Greg Ganske with 43.8% (447,892 votes).
The margin between the first two candidates was 10.4 percentage points (106,386 votes). The party margin (Republican share minus Democratic share) was a Democratic lead of 10.4 points.
Compared with the previous comparable race in the same area, the party margin moved 48.3 points toward Democrats. The winning party changed.
1,023,075 votes were counted in this race, for 4 candidates or options.
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