WATCH: Trump holds campaign rallies at a manufacturing plant in Waunakee, Wisconsin

WAUNAKEE, Wis. (AP) — Former President Donald Trump spent more than an hour before Tuesday night's vice presidential debate campaigning in a Democratic district crucial to Kamala Harris' hopes of winning the key battleground state of Wisconsin.

Watch it in the player above.

The Republican Trump appeared at a manufacturing plant in Waunakee, a suburb of Wisconsin's capital Madison in the Democratic stronghold of Dane County. Trump never campaigned in Dane County or visited as president.

At an event billed as an economic theme, Trump jumped from topic to topic and also criticized Democratic candidate Harris on issues such as foreign policy, crime and immigration, while occasionally turning to outgoing President Joe Biden.

“I ask every citizen to join me in ushering in some kind of new golden age for America,” Trump told hundreds of employees at Dane Manufacturing, a metal fabricator that has long hosted Republican candidates and officeholders.

Later Tuesday, Trump was scheduled to hold an event at a museum in Milwaukee, Wisconsin's largest city and home to the state's most Democratic voters and second-largest Republicans. His appearance there should also give him access to the city's conservative suburbs, a part of Wisconsin where his support has waned but where he needs to do well to win.

Trump is scheduled to speak in Milwaukee at 6 p.m. EDT. Watch live below.

Last Saturday, he held a rally in western Wisconsin where he blamed Harris for crimes committed by people in the country illegally.

Both of his scheduled stops came ahead of Tuesday's debate in New York between Trump's vice presidential nominee JD Vance, a senator from Ohio, and Democratic vice presidential candidate Tim Walz, the governor of Minnesota.

Dane County, the site of Trump's first stop, is Wisconsin's fastest-growing county and an economic engine for the state, fueled by jobs in the health care and technology industries. The University of Wisconsin is also located here.

Dane County's population grew by about 30,000 people between 2016 and 2020. Since then, it has risen by another 13,000, according to the latest U.S. Census Bureau estimate.

That presents a challenge for Republicans, especially considering that nearly 90% of registered voters in the county cast ballots in 2020. Biden won 75% of the vote in Dane County this year, beating Trump in the county by 181,000 votes while leading the state by fewer than 21,000. Hillary Clinton beat Trump by 47 points in Dane County in 2016, and Trump won the state by less than a point.

That's a point that former Wisconsin Gov. Tommy Thompson raised with Trump. Addressing the crowd before Trump's arrival, Thompson said the former president should “go where the opposition is.”

“And the answer was, 'Isn't Madison very liberal?'” Thompson said. “Yes, but Dane County has the third most Republican votes in the state of Wisconsin and we just need to increase it.”

Democratic presidential candidates have long come to Dane County to hold large rallies to fire up the base. Harris campaigned there on September 20 and held a rally in Madison that drew more than 10,000 people.

Waunakee, which bills itself as “the only Waunakee in the world,” is slightly more Republican than the county as a whole. In 2020, Trump received 36% of the vote there, compared to less than 23% nationally.

In Milwaukee, Trump was scheduled to speak at Discovery World, a science and technology museum on the shores of Lake Michigan.