Tuesday, voters go to the polls in the South Dakota and Iowa primaries. In the Hawkeye state, Republican have a lot of candidates to choose from in legislative races. That's especially true in the House, where 26 seats held by Republicans have contested races in Tuesday's election. The GOP has 10 primary races in the Senate including three incumbents facing challenges. Democrats have four primary races. The abundance of candidates is in part a result of redistricting. The new legislative maps put 41 lawmakers in new districts with other incumbents.