Democrat Catelin Drey captured Iowa’s vacant Senate District 1 seat on Tuesday, defeating Republican Christopher Prosch with about 55 percent of the vote, according to unofficial results from the Woodbury County auditor. Prosch drew roughly 45 percent. The double-digit victory in north-western Iowa overturns a district that President Donald Trump carried by 11 points in 2024 and that the late Republican incumbent Rocky De Witt won by 10 points in 2022, marking a swing of almost 20 percentage points toward Democrats. Drey’s win reduces the Republican caucus to 33 seats in the 50-member chamber, ending the two-thirds supermajority the party has held since 2022. Without that margin, Governor Kim Reynolds will need at least one Democratic vote to confirm executive and judicial nominees, potentially complicating the final year of her term. The contest drew outsized national attention. The Democratic National Committee said it deployed about 30,000 volunteers and significant in-kind spending to the race, while the Iowa GOP provided more than $160,000 in support for Prosch. Republicans dismissed the result as a low-turnout anomaly, but it is the second time this year Democrats have flipped an Iowa Senate seat after their January victory in District 35. State party strategists on both sides are reading the outcome as an early signal for the 2026 midterms. Through late August, Democratic candidates have averaged high-teen over-performances in special elections compared with last year’s statewide results, a trend now reinforced in one of Iowa’s most reliably conservative districts.