EAU CLAIRE, Wis. (NewsNation) — With 90 days until the 2024 presidential election, Democratic nominee Vice President Kamala Harris and running mate Minnesota Gov. Tim Walz are focusing their campaign efforts on key battleground states, beginning in Wisconsin.

Greeting in a high-five hand clasp with Walz, Harris joined her new running mate at the outdoor rally in Eau Claire.

“Give it up for Wisconsin’s own Bon Iver,” she said, thanking the opening band, which was founded in the northwest Wisconsin city.

And asking for a round of applause for Biden, the crowd of thousands at the Eau Claire Event District began chanting, “Thank you, Joe! Thank you, Joe!”

Walz, introduced Tuesday in Philadelphia, criticized Republican nominee former President Donald Trump and his running mate, Ohio Sen. JD Vance.

As the race intensifies, the challenge now is to define Walz to Americans, as Republicans criticize his progressive policies as governor.

Vance was also in town for his own rally.

How have Democrats responded to Walz as Harris’ running mate?

Democrats nationwide have been quick to endorse Walz.

The Harris campaign reported raising more than $20 million following the announcement of Walz as the VP pick. Supporters swarmed his house in the Twin Cities after the announcement.

Walz was the first person to start the “these guys are weird” attacks on Trump and Vance.

Now, Harris and Walz are embracing pop culture, with Walz wearing a campaign hat resembling pop star Chappell Roan’s merchandise. However, it’s too early to tell if the excitement among Generation Z will lead to actual votes.

The duo made their first appearance together as running mates Tuesday in Philadelphia, where the crowd was full of energy and Walz immediately targeted Vance in his remarks.

“Like all regular people I grew up with in the heartland, JD studied at Yale, had his career funded by Silicon Valley billionaires, and then wrote a bestseller trashing that community. Come on, that’s not what middle America is,” Walz said.

What are Republicans saying about Walz as the VP pick?

Republicans have been quick to come at Walz.

Trump reposted an article on Truth Social attacking the governor for retiring from the National Guard before troops deployed to Iraq in 2005; Walz successfully ran for Congress in 2006.

Vance accused Walz of being soft on crime.

“They make an interesting tag team because of course Tim Walz allowed rioters to burn down Minneapolis in the summer of 2020, and then the few who got caught, Kamala Harris helped bail them out of jail. So, it is more instructive for what it says about Kamala Harris, that she doesn’t care about the border, she doesn’t care about crime.”

Former GOP candidate and South Carolina Gov. Nikki Haley also went after Walz in a post on social media platform X.

“Democrats doubling down on the Progressive movement,” she said. “Walz is a win for open borders, socialism and Iran.”