OSHKOSH, Wis. — With the Democratic National Convention set to kick off, President Trump offered a dose of counter programming on Monday, campaigning the oldfashioned way despite the coronavirus pandemic.

After making stops in Minnesota earlier in the day, the president traveled to the battleground state of Wisconsin, where at least 700 supporters gathered for an event at Wittman Regional Airport in Oshkosh and cheered wildly as Air Force One landed.

Plenty of red hats but few masks could be seen in the shoulder-to-shoulder crowd, which was overwhelmingly white and older. “Four more years!” the crowd chanted.

Supporters mostly cheered Mr. Trump’s talking points, such as support for gun rights, law enforcement and rebuilding the economy. “Do you want to defund and defame and dismantle the police?” Mr. Trump said. “I don’t think so.”

The applause faltered noticeably, however, when the president brought up the topic of the coronavirus. “We handled it,” he said. “We handled it well.”

Oshkosh is in Winnebago County, which voted for Barack Obama in 2008 and 2012, but swung to Mr. Trump in 2016. The president’s visit was the latest example of what is turning out to be an asymmetrical campaign, with Mr. Trump making in-person appearances before crowds while his Democratic opponent, Joseph R. Biden Jr., refrains from holding rally-style events.

Democrats had planned to hold an in-person convention in Milwaukee this week, but the gathering will now be mostly virtual, and Mr. Biden will not be traveling to Wisconsin.

Speaking hours before the Democratic convention began, Mr. Trump suggested the upcoming programming would not be enticing. “Who wants to listen to Michelle Obama do a taped speech?” he asked.

Kay Nolan reported from Oshkosh, and Thomas Kaplan from Wilmington, Del.