Iowa Senate: Ernst Out, Republicans Still Favored
August 29, 2025 · 2:20 PM EDT
By Jacob Rubashkin & Nathan L. Gonzales
Republican Sen. Joni Ernst will not run for re-election, according to CBS News and several other outlets. The Iowa senator’s plans had been the subject of rumors in Washington, DC for months, after a rocky start to the year prompted speculation that she would not run for a third term.
Iowa already sat at the edge of the Senate battleground, a reach for Democrats after a decade of Hawkeye losses but also a critical part of their narrow path back to the majority. Four Democrats are currently running: state Sen. Zach Wahls, state Rep. Josh Turek, mechanic/veteran Nathan Sage, and Des Moines School Board chairwoman Jackie Norris.
Even without an official announcement from Ernst, there has been plenty of jockeying behind the scenes as Republicans prepared for this possibility. 2nd District Rep. Ashley Hinson, who represents the northeast quadrant of the state, is the most likely to run and would be a formidable candidate. She ousted an incumbent Democrat in 2020 and won easy re-elections in 2022 and 2024.
US Ambassador to NATO Matthew Whitaker is also a potential candidate. The former acting Attorney General served as the U.S. Attorney for the Southern District of Iowa in the George W. Bush administration. He also ran for the GOP Senate nomination in 2014, placing fourth behind Ernst and two others.
Rep. Zach Nunn represents the 3rd District and has statewide ambitions. He twice considered running for governor this year, but is unlikely to run for Senate. The White House had previously pressured Nunn to stay in his swingy Des Moines district rather than force Republicans to defend a vulnerable open seat.
It’s unclear what role President Donald Trump would play or who he would endorse in a potential primary.
It will take some time for the dust to settle after Ernst’s decision. Open seats are generally harder for a party to defend but a candidate like Hinson, who doesn’t have some of Ernst’s specific baggage, could have fewer headaches for the GOP. And it’s unclear what the national political environment will be and how Iowa will be impacted. For now, we’re maintaining our Likely Republican rating.
If Hinson runs for the Senate, her 2nd District race (currently rated Likely Republican) could get more competitive. And if Nunn runs, his 3rd District seat (currently rated Lean Republican) would be more vulnerable to a Democratic takeover. Nunn won by 4 points in 2024.
Overall, Democrats need a net gain of four seats and Republicans have the advantage to hold their majority. The path for Democrats would be to hold all of their own seats (which is not a given), win the open seat in North Carolina, somehow dislodge Sen. Susan Collins in Maine and then win two of Iowa, Texas, Ohio, or Alaska. It’s possible but not likely, with more than a year to go.
Ernst is the eighth senator to announce they will not seek re-election. She joins four Democrats (Gary Peters of Michigan, Tina Smith of Minnesota, Jeanne Shaheen of New Hampshire and Dick Durbin of Illinois) and three fellow Republicans (Tommy Tuberville of Alabama, Mitch McConnell of Kentucky and Thom Tillis of North Carolina). There’s been an average of at least five open Senate seats each election year since Herbert Hoover was president and there were only 48 states in the union.