Zach Nunn Is Challenged by Democrat Sarah Trone Garriott in the 3Rd District

The Trump administration is sending top officials to Iowa over the coming days to help Republican candidates in competitive races, sources familiar with the matter told CBS News. Treasury Secretary Scott Bessent, U.S. Trade Representative Jamieson Greer, Small Business Administration Administrator Kelly Loeffler, Veterans Affairs Secretary Doug Collins and U.S. Ambassador to NATO Matt Whitaker are among those expected to campaign in the state. The Iowa State Fair, which opens Thursday and runs through Aug.

Republican Rep. Mariannette Miller-Meeks faces Democrat Christina Bohannan in Iowa's 1st Congressional District, while Rep. Zach Nunn is challenged by Democrat Sarah Trone Garriott in the 3rd District.

Republican Rep. Ashley Hinson is running for U.S. Senate against Democrat Josh Turek. Specific schedules for the visiting officials in Iowa were not immediately available.

House Majority Leader Steve Scalise was in Iowa on Wednesday, joined by Republican National Committee Chairman Joe Gruters and Republican Reps. Jason Smith of Missouri, Pete Stauber of Minnesota and Glenn Grothman of Wisconsin. This is a developing story and will be updated.