Derek Merrin won the Republican primary in Ohio's 9th Congressional District on Tuesday, CBS News projected, setting up a rematch against longtime Democratic Rep. Marcy Kaptur in what's expected to be one of the most contested House races of the year. 

Kaptur, the longest serving woman in Congress, has held the seat since 1983. 

Merrin, a former state representative, tried to unseat Kaptur in 2024, but lost by about 2,400 votes — just above the threshold needed to trigger an automatic recount. The race wasn't called until two weeks after the election. 

But the northwestern Ohio district was redrawn in October 2025, creating a more Republican-leaning seat ahead of November. The change is expected to put Kaptur in her toughest bid yet for reelection as Republicans try to maintain control of the House. The Cook Political Report has rated the district a toss up. 

The National Republican Campaign Committee is focused on flipping the 9th District, saying in January that "Republicans are poised to flip OH-09 red and retire out of touch, career politician Marcy Kaptur. Kaptur should go ahead and start cleaning out her office now."

Merrin beat four other GOP candidates on the primary ballot, including state Rep. Josh Williams, former Immigrations and Customs Enforcement official Madison Sheahan, health care data scientist Anthony Campbell and Air Force veteran Alea Nadeem. 

Sheahan was a controversial late entry in the race, and has campaigned on her role at ICE, and racked up endorsements from former Ohio State University coach Urban Meyer and MAGA celebrity Ted Nugent. But she struggled to gain traction in the crowded field.

Williams, 41, told CBS Toledo affiliate WTOL that Kaptur "has been in Congress longer than I've been alive." Both Williams and Merrin touted their conservative credentials and longtime leadership in the district.