Voters cast ballots for the midterm elections at the Polk County Election Office in Des Moines, Iowa.

Voters cast ballots for the midterm elections at the Polk County Election Office in Des Moines, Iowa.

Voters cast ballots for the midterm elections at the Polk County Election Office in Des Moines, Iowa.

Fred Hubbell, Democratic candidate for governor of Iowa, speaks to supporters at a get-out-the-vote rally he was hosting with Cindy Axne, democratic candidate for the U.S. House in Iowa's 3rd district in Des Moines, Iowa.