Iowa is no stranger to political attention in presidential elections, but surprisingly competitive midterm contests highlight the state's importance for both parties as it holds its primary Tuesday.

Iowa is no stranger to political attention in presidential elections, but surprisingly competitive midterm contests highlight the state's importance for both parties as it holds…

While Republicans hold an advantage in Iowa, Democrats see openings in an open governor’s and Senate race, and two congressional districts.

The winners will compete in November’s critical midterm elections, in which Iowa’s U.S. Senate and House seats could determine control of the narrowly divided chambers.