Gov. JB Pritzker speaks in Chicago while on shortlist for Kamala Harris' VP pick

CHICAGO (WLS) -- It has been a quick vetting process for the Harris campaign.

Vice President Kamala Harris is expected announce her running mate on Tuesday morning after a Monday evening rally in Philadelphia. Harris and her running mate will then travel to several swing states over the next five days.

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As he arrived for work in Harrisburg, Pennsylvania, Gov. Josh Shapiro was tight lipped about his vice-presidential prospects.

"I've got nothing for you man, have a great day," Shapiro said.

The popular Pennsylvania governor is considered to be one of Harris' top tier picks, and so is Minnesota Gov. Tim Walz.

"He's got a really interesting history, a military background, winning a congressional district that was a swing district popular even in some Republican areas of Minnesota," said Elmhurst College Political Science Professor Connie Mixon.

Walz is also a former teacher with a folksy manner who political scientists say appeals to progressives and rural white, blue-collar Midwest voters. But Shapiro could help Harris close the gap against Trump in Pennsylvania and win the critical swing state.

"I really feel as if all roads have to go through Pennsylvania. Pennsylvania has 19 Electoral College votes. You could lose Arizona and Nevada, but you have to get Pennsylvania," Mixon said.

While far-left pro-Palestinian groups may object to a Shapiro pick because he is Jewish, Mixon does not believe his religion and pro-Israel stance will make or break the election. Shapiro and Walz were vetted by the Harris campaign along with four others, including Illinois Gov. JB Pritzker.

"Unfortunately, politics these days sometimes obscures the difference between right and wrong, and it's the people in this room and stand in the breach," Pritzker said.

Briefly speaking before the American Bar Association conference, Pritzker did not talk to the media during his only public appearance on Monday. He told attendees he is concerned about the threats to the rule of law and democratic norms in the U.S.

In the meantime, some Illinois Republicans say Harris' vice-presidential pick is inconsequential, because they will vote for her no matter what.

Former Illinois Congressmen Joe Walsh and Adam Kinzinger, former Transportation Secretary Ray LaHood and former Gov. Jim Edgar are launching a group called Republicans for Harris.

"We believe for a while, that Donald Trump is unfit to be president, and so we are all rallying behind the only person who can beat him, and that's Kamala Harris," said former Republican Illinois Congressman Joe Walsh. "We're going to try to activate Republicans especially in the battleground states to make a difference."