Donald Trump leaves for Montgomery County on Monday.

The visit to Oaks for a town hall will be Trump’s first public campaign event in suburban Philadelphia of the 2024 campaign. It will also mark his fourth event in Pennsylvania since returning to Butler, the site of his assassination attempt, on October 5.

Trump has focused lately on the kind of white working class that helped him get elected in 2016. He attended a private fundraiser in Bucks County this spring but focused his campaigning elsewhere. But Philadelphia’s suburbs will play a key role in winning state. The suburbs are home to the largest number of voters in Pennsylvania. Suburban voters gave President Joe Biden the most votes of any regional group in the state in 2020, and Trump drew his second-largest vote share from the suburbs, behind rural parts of the state.

Oaks, home to the Greater Philadelphia Expo Center & Fairgrounds where Trump will appear, is surrounded by Collegeville, King of Prussia, and Phoenixville, in Chester County, all places that have turned blue in recent elections. But Republicans who want to win statewide will have to cut those margins.

According to his campaign, Trump’s town hall will focus on the economy. A town hall format scheduled for Wednesday in Scranton turned into a rally featuring Trump’s standard, rambling speech.

To appeal to more moderate voters in the Montgomery County region, Trump may need to sharpen his message. A quarter of Montgomery County’s Republican primary voters voted for former South Carolina Gov. Nikki Haley in the GOP primary months after she withdrew from the race. They have become a bloc that Vice President Kamala Harris’ campaign is trying to appeal to in a closely divided state.

“Gas and diesel prices reached historic highs thanks to the Harris-Biden administration’s crackdown on American energy and fracking in Pennsylvania,” the Trump campaign said in a statement previewing the campaign event. “More broadly, Pennsylvania has been on the receiving end of America’s lopsided trade deals, allowing foreign adversaries to erode our industry.”

With three weeks to go and the race in a dead heat, weekly attendances are increasing.

Trump’s visit comes on the same day that Harris will campaign in Erie, a county on the other side of the state. The suburbs are a popular campaign stop in the coming days, with Harris’ husband Doug Emhoff visiting this weekend, and first lady Jill Biden and Trump’s running mate, Ohio Sen. J.D. Vance, campaigning in Montgomery County on Tuesday.

Both the campaigns and the outside groups backing them have spent an avalanche of money in the state — more than on any other battleground. And they’ve had more visits here than anywhere else in the hunt for the 19 electoral votes that could very well determine who goes to the White House.