Two Republicans face off in Warren County Commission primary

Challenger Mark Messer has been the mayor of Lebanon since 2021. Prior, he served for 10 years on the Lebanon City Council, eight of those as vice mayor.

The winner will face off against two challengers who are unopposed in the primary: Libertarian Katherine Bowles of Lebanon and Democrat Ian Logan of Mason.

The commissioner position paid $103,829 in 2026, according to the county auditor’s office.

The winner of the November General Election will take office Jan. 1, 2027 and serve through Dec. 31, 2030.

We asked the primary candidates a series of questions to help voters make their decision on May 5:

Tom Grossmann

Why do you want the office?

I have been a Commissioner since January 2015 and have succeeded in making a positive impact for the county and its residents. After I became a Commissioner, our county’s financial performance earned a top triple A bond rating from Moody’s Ratings, which we have maintained; all county debt was retired; for the first time county residents were given a total real estate property tax break of $46 million in 2022 (we are seeking to do it again this year); a new county jail, new county court house, and other new county facilities were built, and still we have no debt; we lowered the county sales tax; we developed a sports park that brings in increased sales tax revenue; we saved the ATP tennis tournament from leaving; and we improved our level of services while keeping taxes low. I have a proven record of accomplishment. My opponent concedes under my leadership we have “the best run county in the country” (Feb. 10, 2026 Candidate Meeting with the Warren County GOP). Our county is ranked by U.S. News & World Report in the top 3% of all counties in the U.S.

What differentiates you from your opponent?

I have a long and strong record of experience and success as a commissioner and he does not. I have a record of resident friendly tax decisions and he does not. I have a background and record of supporting the farming and business communities of Warren County and he does not. I have a strong record of living and supporting conservative, Republican values and he does not. I have the education, background and experience that qualifies me to address the complex issues of a large county and he does not. When I was on Mason’s council and its mayor, I authored a Mason Charter Amendment giving complete credit for all earnings taxes paid to other cities, saving Mason residents $2.5 million annually. My opponent doubled taxes on Lebanon residents who pay another city’s earnings tax if it exceeds 1%. I ensured Mason residents pay no more than a 1% earnings tax to Mason. My opponent promoted and then raised Lebanon’s earnings tax by 50%, from 1% to 1.5%. This huge tax increase was hidden by a slight property tax decrease enacted at the same time, a 3-mil property tax decrease, $105 on $100,000 in market value, compared to a $500 earnings tax increase on $100,000 in earnings. As a small business owner and farmer, I bring a unique set of skills, experiences and interests with a heart to promote and maintain our agricultural county heritage. The county has about 260,000 acres, 101,621 of which is farmed. As a lawyer, I have the ability to address difficult legal and zoning issues that come before the commission. I have a record of accomplishment for the county and of conservative action. I helped found and was on the board of the Center for Christian Virtue for 25 years, formerly Citizens for Community Values. I helped found and was the president of the Cincinnati chapter of the conservative legal group The Federalist Society, was the legal counsel for the Home School Legal Defense Fund, and was on the advisory board of the first Cincinnati Crisis Pregnancy Center. I have represented peaceful pro-life protesters at abortion clinics in Cincinnati and Dayton. I was the chairman of the Warren County Republican Party for 8 years and was on the boards of the Dan Beard Council, Scouting America (formerly the Boy Scouts) and the Atrium Medical Center.

What do you see as the biggest issues facing Warren County and the region over the next 8 years and how do you plan to address them?

Since I became a commissioner, Warren County has been one of the fastest growing counties in Ohio. In 2014 we had about 221,000 residents. In 2026 the county will have about 261,000 residents. In the last decade our population has increased by 18%. In the next decade, we may have over 300,000 residents. To address this, we must have balanced residential and business growth. This requires careful planning, zoning, economic development and programs that maintain our current business community and that encourages new businesses and investment. Businesses bring in good, new jobs which support our tax base; fund needed infrastructure, road and utility improvements; and support our schools helping to keep taxes low. I was on Mason’s council, as both a former mayor and vice-mayor. As a council member, I helped Mason grow its business base. As a commissioner, I have brought that same ability to the county. We are currently working on development projects in Franklin and at state Route 122 and Union Road.

Where do you stand on property tax reform?

I would like to see reform of our property tax laws with higher exemptions and lower property taxes for senior citizens, but it is not within the power of the county commission to make fundamental changes in property taxes. Our current county tax revenue budget projection for 2026 is $107.6 million. Our primary current revenue sources are the sales tax and property taxes. If property taxes are abolished, the only current viable alternative will be an increase in sales taxes. About 70% of the property tax funds our schools. Warren County has some of the best schools in the state. The issue is how do we fund our schools if the property tax is eliminated. The state legislature is working on those questions.

Mark Messer

Why do you want the office?

I’m running because Warren County deserves leadership that is present, accountable, and focused on results. For the past 14 years, I’ve helped lead the City of Lebanon through responsible growth: balancing budgets, investing over $100 million in infrastructure, securing more than $30 million in grants, $248 million in private-public economic development partnerships in the past 5 years, and reducing debt without raising taxes. Warren County is at a critical moment. Growth is accelerating, costs are rising, and decisions made today will shape the next generation. I’m stepping forward to bring proven, disciplined leadership to the county level.

What differentiates you from your opponent?

This race comes down to accountability and priorities. Warren County deserves a commissioner who shows up, does the work, and puts the public first. There has been a pattern of missed and canceled meetings and a lack of engagement. That’s not acceptable for a role with this responsibility. I believe this job requires full-time focus, transparency, and accountability to the taxpayers and that’s exactly what I will bring. Warren County deserves leadership, not absence. I’ve spent over a decade showing up, doing the work, and delivering results. As mayor, I’ve made tough decisions, overseen complex budgets, and remained accessible to the people I serve. Voters won’t have to wonder where I stand or whether I’ll show up. My record answers that.

What are the biggest issues facing the county over the next 8 years?

The defining challenge is managing growth without losing what makes Warren County special. We’re one of the fastest-growing regions in Ohio. That brings opportunity, but also pressure on infrastructure, services, and housing affordability. My approach is simple:

The growth that is coming to Warren County should work for its residents not just happen to them.

Where do you stand on property tax reform?

Property taxes are one of the biggest concerns I hear from residents, and the system needs reform. The state legislature has provided counties with tools to help relieve the burden of property taxes and I support the use of those tools. In fact, I wrote a letter to my opponent months ago to advocate that Warren County, like our neighbors in Butler County, put those tools to work immediately to help cut property taxes. To this day, I have never received a response, and I am personally stunned that there have not been any steps taken to tackle this problem given the authority vested in them by the state. This lack of urgency is a problem I will fix. As a mayor I know the importance of leadership that is willing to act while also preparing for long-term reform. If broader changes occur, we must ensure essential services remain funded without shifting the burden back onto working families.