Wausau Mayor Katie Rosenberg loses reelection bid

Wausau voters ousted Mayor Katie Rosenberg, electing conservative challenger Doug Diny with 52 percent of the vote.

Wausau spent millions modifying a new water treatment facility after testing in 2022 found all city wells contained elevated PFAS levels. The city instituted new filtration systems in early 2023, but facility costs led to skyrocketing water bills that became an issue in the local race. 

Diny, who was elected to Wausau City Council in 2020, won 5,222 votes to Rosenberg’s 4,798.

Like many local races, the nominally nonpartisan race was characterized by ideological spending on both sides. According to WisPolitics, the state Democratic Party spent $191,000 in ad buys supporting Rosenberg. Diny spent about $92,000 on ads, according to the site, and received $21,800 in donations from the Marathon County Republican Party. Diny also benefited from mailers by the Wisconsinites for Liberty Fund and other sources that attacked Rosenberg.

In his own ads, Diny attacked Rosenberg over “unaffordable water and housing.”

Rosenberg, 40, went viral following her election in 2020 when she tweeted “Holy balls!” in response to her victory. A frequent host of Democratic politicians like Gov. Tony Evers and U.S. Sen. Tammy Baldwin, she was considered a rising star in Democratic circles and a potential candidate for lieutenant governor in 2022. Diny’s victory was an upset.

With about 40,000 residents, Wausau is the largest city in north central Wisconsin. It is a population hub for the mostly rural 7th Congressional District, which as a whole is heavily Republican. It is the county seat of Marathon County, which consistently votes Republican. But the city of Wausau itself is Democratic-leaning and voted for Joe Biden in 2020.

In statements Tuesday night, Rosenberg and Diny thanked their supporters.

“There’s still a lot of work that the next stewards of our city will need to continue,” Rosenberg wrote on social media. “I hope you can support them.”

In his statement, Diny also thanked Rosenberg for her service, and said, “I want every Wausonian to know that I will be a mayor for all.”