Stakes are high for Minnesota Gov. Tim Walz on Election Day

"It is a privilege to be in this moment," Walz said Monday afternoon at a campaign event in Wisconsin. "This is our moment."

It's a scenario few could have envisioned earlier this year, when President Joe Biden was seeking re-election with Harris as his running mate. Walz was mostly unknown outside Minnesota at the time, but his star began to rise as he led the Democratic Governors Association and campaigned as a surrogate for the Biden administration. Walz wasted little time after Biden exited the race, hitting the cable news circuit in an apparent audition to be Harris' running mate. He won over Harris and national Democrats with his "Minnesota nice" way of attacking Republicans as "weird people."

If Harris loses, her selection of Walz over swing-state politicians like Pennsylvania Gov. Josh Shapiro could be subject to fresh criticism. Some questioned the upside of picking a running mate from a state that hasn't supported a Republican presidential candidate in more than 50 years. Harris wagered that Walz's small-town roots and background as a former soldier, teacher and football coach would strengthen her appeal to working-class voters in battleground states.

Walz's joyful, energetic attitude was a hit with Democrats on the campaign trail. Many who attended his rallies proudly waved "Coach!" signs and donned camouflage "Harris-Walz" hats, a nod to the governor's experience as a hunter.

But it's unclear how much of an effect Walz had on undecided voters. The governor struggled at times during his only nationally televised debate against Vance. And Walz sometimes found himself under national scrutiny for past statements he made that were proven inaccurate .

Walz made his final campaign swing Monday in the critical "Blue Wall" states of Wisconsin and Michigan, and he was set to visit Pennsylvania on Tuesday morning before heading to Washington, D.C., for the campaign's election-night party at Howard University.

The governor reflected on his whirlwind journey as the gravity of the moment sunk in on Monday. The Democrat who grew up in rural Nebraska and was first elected to public office just 18 years ago could soon find himself in the White House.

"How amazing is it that a kid from Butte, Neb., and a kid from Oakland, Calif. — middle-class kids, her with a single mom trying to buy a home, me with a dad who dies when I'm a teenager and my little brother's in elementary school, my mom's a stay-at-home mom — but because of what this country has given us and the opportunities, we are going to be the next president and vice president of the United States," Walz said.

A Harris-Walz victory in Tuesday's general election would be historically significant nationally and in Minnesota. Harris would be the first woman elected as president of the United States. And the elevation of Walz would make way for Lt. Gov. Peggy Flanagan to become Minnesota's first female and first Native American governor.