U.S. Vice President and Democratic presidential candidate Kamala Harris and her running mate Minnesota Governor Tim Walz walk as they prepare to depart at Chippewa Airport in Eau Claire, Wisconsin, U.S., August 7, 2024. / REUTERS/Kevin Mohatt

EAU CLAIRE, Wisconsin/DETROIT (Reuters) -Democratic presidential candidate Kamala Harris and her new running mate, Minnesota Governor Tim Walz, put his Midwestern credentials to the test on Aug.8 with rallies in the battleground states of Wisconsin and Michigan.

"Hello, Eau Claire!" Walz said to a boisterous crowd of thousands in the Wisconsin city about 80 miles (130 km) away from his home across the Minnesota border. "Isn't it good to have a candidate who can pronounce the name correctly?"

The Democratic candidates are using their first joint campaign swing to introduce Walz, a former teacher and football coach and a veteran of the Army National Guard, to voters around the country after he beat out better-known Democrats for the No. 2 spot.

They are also making their case against Republican rival Donald Trump and his running mate, U.S. Senator JD Vance, with less than three months until the Nov. 5 election.

"We are joyful warriors," Harris said at an evening rally in Detroit, underscoring the sense of optimism that has enveloped Democrats since she replaced President Joe Biden at the top of the presidential ticket two weeks ago.

Polls show Harris has erased the lead Trump had built during the final faltering weeks of Biden's campaign, and a re-energized Democratic Party has flooded her campaign with donations.

The Harris campaign said it raised $36 million in 24 hours after announcing Walz as the vice presidential pick on Tuesday. Wednesday's rallies drew more than 27,000 people in total, according to the campaign.

Democrats regard Wisconsin and Michigan as near must-win in the 2024 election. The states have loomed large for the party since Hillary Clinton's unexpected defeats there helped clinch Trump's 2016 win.

Biden beat Trump in both states in 2020. But opinion polls showed him facing a close battle in Michigan before his exit, with many members of the state's significant Arab and Muslim American population fuming over the humanitarian crisis of Israel's war against Hamas in Gaza.

In a reminder of how divisive the issue has been for Democrats, a group of pro-Palestinian protesters briefly interrupted Harris' speech in Detroit, chanting, "Kamala, Kamala, you can't hide, we won't vote for genocide."

She paused for a moment, saying she believed in democracy and the importance of every voice, and then added, "But I am speaking now." When the chants continued, she repeated, "You know what? If you want Donald Trump to win, then say that. Otherwise, I'm speaking."

The moment was reminiscent of a viral moment from her vice presidential debate in 2020 when she told an interrupting Republican Mike Pence, "Mr. Vice President, I'm speaking."

Some pro-Palestinian activists see Harris as more of an ally than Biden given her more forceful public comments on Palestinian human rights, even though the two Democrats have displayed no substantive policy differences. Those left-leaning activists also expressed more support for Walz than some other candidates to be Harris' running mate, particularly Pennsylvania Governor Josh Shapiro.

CROSSING PATHS

A former congressman who won elections in a Republican-leaning district before becoming governor, Walz has a record of appealing to the white, rural voters who have increasingly turned to Trump over the years.

But Trump and Vance have portrayed Walz as too left-wing, echoing their criticisms of Harris.

With Trump largely off the road this week, Vance has been trailing Harris and Walz around the country and holding campaign events near their rallies, an effort that comes as Harris' surge appears to have rattled the Trump camp.

In an unusual moment on Aug.7, Vance approached Air Force Two while Harris appeared to be in her motorcade on the tarmac in Wisconsin and asked nearby reporters why she did not take more of their questions.

The two candidates' planes were several hundred yards apart at Chippewa Valley Regional Airport in Eau Claire.

Vance said he was trying to "check out this plane that's going to be mine in a few months" and briefly spoke to reporters while Harris' motorcade drove away, video taken by reporters showed.

Harris' campaign did not immediately respond to a request for comment on the incident, which several people traveling with the vice president said went unnoticed at the time.

Harris and Vance postponed planned events for  Aug.8 across Georgia and North Carolina due to Tropical Storm Debby.

Earlier in the day in Detroit, ahead of Harris' and Walz's scheduled evening rally there, Vance tried out some attack lines on his Democratic counterpart, criticizing Walz's handling of the protests in Minneapolis following the killing of George Floyd there by police in 2020.

Vance, who served in the Marine Corps and was a public affairs officer during a six-month stint in Iraq, also slammed Walz's military record, saying he abandoned his National Guard battalion right before its deployment to Iraq in 2005. Walz, who served in the Guard for 24 years, retired to run for Congress.

In a Fox News interview on Aug.7, Trump said he would debate Harris in the "pretty near future" and that details would be announced soon. He said his preference was for Fox to host the debate.

Last week, Trump proposed a debate with Harris on Fox on Sept. 4. The Harris campaign said Trump was trying to back out of a debate that had already been set with ABC on Sept. 10, before Biden dropped out of the race.