MADISON, WIS. — U.S. Rep. Tom Tiffany, a Republican running for governor of Wisconsin, acknowledged his party's poor performance in Tuesday's elections after Democrats won a Wisconsin Supreme Court seat and the mayoralty of Waukesha, a traditionally conservative city. "We got our butts kicked," Tiffany said.

In the Wisconsin Supreme Court race held Tuesday, the liberal-backed candidate won by 20 percentage points, expanding the liberal majority on the court. Democratic candidates improved their performance across counties of all partisan leanings compared to a similar judicial race last year, according to vote tallies. In the Waukesha mayoral contest, Alicia Halvensleben, president of Waukesha's Common Council, defeated Scott Allen, one of the most conservative members of the Wisconsin State Assembly.

The results prompted differing assessments from the two parties' leaders in Wisconsin. Wisconsin Democratic Party Chairman Devin Remiker said the outcomes pointed toward continued Democratic strength in the fall elections. "This to me was a very clear sign of momentum and enthusiasm for Democrats in the fall," Remiker said.

Wisconsin has an open gubernatorial race this year, and Democrats also aim to take control of the state Legislature and to oust Republican U.S. Rep. Derrick Van Orden from Congress.

Tiffany, who represents Wisconsin's 7th Congressional District and is seeking the governorship, said he was not making any changes to his campaign in response to Tuesday's results. "Every election is unique," Tiffany said.

The 20-point margin in the Supreme Court race was a wide gap in a state where statewide contests have frequently been decided by single digits. The improvement in Democratic performance across counties of varying partisan composition indicated the party's gains extended beyond its traditional bases of support in cities such as Milwaukee and Madison.

In Waukesha, Halvensleben's victory over Allen was a setback for Republicans in a city in southeastern Wisconsin that the party has long carried in statewide elections. Allen had entered the mayoral race as a sitting state Assembly member.