Why did Kamala Harris choose Tim Walz over Josh Shapiro for VP? Expert weighs in

PHILADELPHIA -- Vice President Kamala Harris' choice of Minnesota Governor Tim Walz as her running mate, and former President Donald Trump's choice of Ohio Senator JD Vance as his running mate, clearly shows how important the Rust Belt is to both parties in the race for the White House.

Case in point was Harris introducing Walz as her vice presidential pick in the home state of one of her other top choices, Pennsylvania Governor Josh Shapiro.

"I think both Shapiro and Walz had risks and rewards for her and one of the reasons people pay attention to veepstakes is because it says something about the candidate," noted Dr. Susan Liebell, a political science professor at St. Joseph's University.

"I think what she's trying to do is throw something to progressives to say, 'I do care about these policies.' But she's also saying, 'I know this race is going to be won in Michigan, Wisconsin, and Western Pennsylvania,'" Liebell added.

She believes Harris is taking a calculated risk by solidifying her commitment to progressive policies in choosing Walz over the more centrist Shapiro.

RELATED | Shapiro had reservations about leaving job as Pa. governor after Harris meeting: ABC News sources

But how much of a difference does a presidential running mate make?

A few people who spoke with 6abc Action News said it makes a substantial difference.

Most, however, said not so much.

"I think it's just window dressing," Mere McDonald of North Philadelphia said.

"To a degree, yes, but the head of the ticket is the most important part," added John Arbitell of Center City.

Election Day is just three months away.