BYRON CENTER, Mich. — When it comes to the crucial battlegrounds of Michigan, Pennsylvania, and Wisconsin, long known as the Democrats' ‘blue wall’ states, Republican vice presidential nominee Sen. JD Vance is optimistic they're "going to be the red wall in November."

"We’re going to make sure that Pennsylvania, Wisconsin and Michigan go red," former President Trump's 2024 running mate emphasized in an exclusive national interview with Fox News Digital on the campaign trail in southwestern Michigan this past week.

Democrats reliably won all three working-class states in presidential elections for nearly a quarter-century before Trump narrowly carried them in capturing the White House eight years ago.

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JD Vance at podium

Sen. JD Vance of Ohio, the Republican vice presidential nominee, headlines a Trump campaign event in Byron Center, Michigan, on August 14, 2024.  (Fox News — Paul Steinhauser)

But in 2020, President Biden won back all three states with razor-thin margins as he defeated Trump.

The states remain extremely competitive as Vice President Kamala Harris and Trump face off in the 2024 presidential election.

Last month's Republican National Convention was held in Milwaukee, Wisconsin's largest city. And Trump and Vance held their first join-campaign rally after the convention in Grand Rapids, Michigan, just a few miles north of where Vance was interviewed by Fox News on Wednesday.

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Vance, a first-term populist senator and a leading Trump ally in the Senate, has made stops in all three blue wall states in the past two weeks, and told Fox News that he would be spending plenty of time in the states the rest of the summer and autumn spreading the GOP ticket's working-class message.

"We’re going to make sure that Pennsylvania, Wisconsin and Michigan go red. People are sick of green energy scams that ship our manufacturing jobs to China instead of keeping them right here at home in Michigan, Pennsylvania and Wisconsin. I think we have a great pro-manufacturing, pro-American worker message," he emphasized.

Trump with Vance at GOP convention

Republican presidential nominee former President Trump and GOP vice presidential nominee Sen. J.D. Vance of Ohio appear on the first day of the Republican National Convention at the Fiserv Forum on July 15, 2024, in Milwaukee, Wisconsin. (Photo by Joe Raedle/Getty Images) (Joe Raedle/Getty Images)

Vance said that his pitch to working-class voters is a "core message that Donald Trump and I have in this campaign and this is a good place for people to hear it."

Vance hails from Ohio, which neighbors both Pennsylvania and Michigan, and his Midwestern and working-class roots in a region long known as the ‘Rust Belt’ were likely key factors in Trump's decision to name the senator as his running mate.

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Before running for Senate, Vance grabbed national attention after his book "Hillbilly Elegy" – which tells his story of growing up in a struggling steel mill city and his roots in Appalachian Kentucky – became a New York Times bestseller and was then made into a Netflix film. The story spotlighted the values of many working-class Americans who became supporters of Trump's policies.

Fox News observed as Vance spread his Midwestern folksiness with the owners and family of the trucking company that hosted last week's rally in Michigan.

JD Vance with wife campaigning

Republican Vice Presidential nominee Sen. JD Vance of Ohio and his wife Usha meet with supporters ahead of a campaign event in Byron Center, Michigan on August 14, 2024. (Fox News - Paul Steinhauser)

Holding the baby of one of the family members, the senator — who was accompanied by his wife — said that he wanted a fourth child.

And later, in his speech at the rally, he spotlighted the instrumental role his grandmother "Mamaw" in his life. The comments have become a key ingredient in his stump speech.

"I was one of the lucky ones – I managed to achieve the American Dream. I managed to build a life because I had a Mamaw that was tough as nails," Vance told the crowd.

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Democrats have repeatedly taken aim at Vance, and have argued that he's anything but a working-class hero, as they point to his years in San Francisco as a top hedge fund executive  when he worked as a principal in a venture capital firm owned by billionaire Peter Thiel.

Harris — who replaced Biden last month atop the Democrats' 2024 ticket and who named Minnesota Gov. Tim Walz, another Midwesterner, as her running mate — charges that Vance is a "rubber stamp" for Trump's "extreme agenda" 

"Make no mistake, JD Vance will be loyal only to Trump, not to our country," Harris has said.

Get the latest updates from the 2024 campaign trail, exclusive interviews and more at our Fox News Digital election hub.