Mason and Deerfield Township voters will help decide a toss-up U.S. House race on Nov. 3, according to the Cook Political Report.

Democratic Rep. Greg Landsman faces Republican Eric Conroy for Ohio's 1st Congressional District, which now includes all of Warren County after state lawmakers redrew the boundaries in 2025. The district also covers Clinton County and the eastern and southern parts of Hamilton County.

The new map shifted the district's political lean. Under the old lines, Vice President Kamala Harris carried the district by six points in 2024. Under the new map, President Donald Trump would have won it by three, WLWT reported. Republicans kept Warren County in the district and added Clinton County while removing part of heavily Democratic Cincinnati, according to WVXU.

Landsman, a former public school teacher and Cincinnati council member, is seeking a third term. He told the Dayton Daily News voter guide that his top priority is "improving the economic reality of working people." He said he would work to end tariffs, end the Iran war and get costs down.

Landsman pointed to his record pushing the Social Security Fairness Act through the House and leading the Cincinnati Preschool Promise. He also said he and his wife divested their stock portfolio, arguing members of Congress should not hold stock investments.

Conroy, 37, grew up on Cincinnati's West Side and attended the U.S. Air Force Academy, according to the Ohio Capital Journal. He served seven years as an intelligence officer and then spent seven years at the CIA. Trump endorsed him ahead of the May 5 Republican primary, which Conroy won with 71.9% of the vote.

"Too many members show up to perform for the cameras," Conroy told the Dayton Daily News. "I will show up to find the votes, including across the aisle, to lower costs, keep our neighborhoods safe, and deliver for southwest Ohio."

Conroy said his priorities include lowering costs, making communities safer and reducing red tape for small businesses. He criticized Landsman over stock trades Landsman failed to disclose on time under the STOCK Act, calling it hypocritical given Landsman's anti-corruption platform.

Landsman defended his vote against a stock-trading ban bill, saying it included unrelated provisions he opposed.

The race has drawn national attention. The Associated Press reported that Landsman has raised more money than Conroy in recent quarters. The Congressional Leadership Fund, the leading House Republican super PAC, has invested in the Cincinnati-area race as part of more than $13.3 million spent across competitive districts through Oct. 13, according to AP reporting.

Early voting is underway.

Election Day is Tuesday, Nov. 3.