MADISON, Wis. (AP) -- A shirtless candidate for U.S. Senate broke through the ice of a Madison lake Thursday hoping to pour cold water on any notion that he's a soft Californian, not a hardy Wisconsinite.

And then Eric Hovde challenged his Democratic challenger, U.S. Sen. Tammy Baldwin, to take the plunge as well.

The multimillionaire Republican Hovde is trying to combat attacks from Baldwin and Democrats that he's more Golden State than Dairy State. Hovde was born and raised in Wisconsin, but also owns a $7 million estate in Laguna Beach, California, and is CEO of California-based H Bancorp and its primary subsidiary, Sunwest Bank.

Hovde posted a video on X on Thursday showing him pressing through what he says is about a half-inch (1.3-centimeter) layer of ice on Lake Mendota outside of a home he owns.

"It was hard to break through but it's good to get out here for a good cold plunge," Hovde says before he turns the camera on his shirtless torso.

"So the Dems and Sen. Baldwin keep saying I'm not from Wisconsin, which is a complete joke," a laughing Hovde says into the camera. "Alright Sen. Baldwin, why don't you get out here in this frozen lake and let's really see who's from Wisconsin."

Wisconsin Democratic Party spokesperson Arik Wolk doubled down in the face of the challenge.

"If California bank owner Eric Hovde thinks sitting in a lake is going to stop us from telling Wisconsinites about his California bank, California megamansion, and California ties, he's going to be swimming a whole lot for the next eight months," Wolk said in a statement.