Joni Kay Ernst is an American politician and former military officer serving as the junior United States senator from Iowa since 2015. A member of the Republican Party, she previously served in the Iowa State Senate from 2011 to 2014 and as auditor of Montgomery County from 2004 to 2011. As Chair of the Senate Republican Policy Committee since 2023, Ernst is the fourth-ranking Republican in the Senate.

The Republican Party of Iowa (RPI) is the affiliate of the United States Republican Party in Iowa. The State Central Committee is chaired by Jeff Kaufmann. The RPI operates the Republican side of the Iowa caucuses and previously sponsored the Iowa Straw Poll.