The Trump and Harris campaigns are flooding the zone in Pennsylvania this week

With just about three weeks until Election Day, both presidential campaigns are zeroing in on Pennsylvania, a crucial battleground neither candidate can afford to lose.

Vice President Kamala Harris and former President Donald Trump each rallied in Pennsylvania Monday — albeit at opposite ends of the commonwealth. President Joe Biden will fundraise for Democrats in Philadelphia Tuesday, Harris will hold an event in Bucks County Wednesday, and Trump’s running mate, Sen. JD Vance, has at least three events in Pennsylvania this week.

As the candidates and their major surrogates traverse the state to try to close the deal in the campaign’s waning days, each side is also pouring millions of dollars into advertising and field operations across every region in Pennsylvania.

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But little says more about a state’s importance than the amount of time that campaigns — and the candidates themselves — spend in the state. Here’s what this busy week looks like in Pennsylvania.

Harris held a rally Monday evening in Erie, a majority Democratic city in a Northwest Pennsylvania swing county. Erie (the county) has a split electorate and is considered one of the state’s most reliable bellwethers — Trump won the county in 2016, but it swung for Biden in 2020. Trump campaigned in Erie just two weeks ago. It will be Harris’ 10th visit to Pennsylvania.

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Gwen Walz, the wife of Harris’ running mate, Minnesota Gov. Tim Walz, also campaigned for Harris in Easton, Northampton County, as well as in Chester County. Northampton is considered a potentially determinative swing county.

In what was his first public event of the campaign in the Philadelphia suburbs, Trump held a town hall event in Oaks, Montgomery County, Monday. While the area has trended Democratic, the Trump campaign and its allied groups are trying to cut into Harris’ margins in the voter-rich suburbs, which helped deliver the state to Biden in 2020.

The event is Trump’s fourth in Pennsylvania in just the last 10 days. He held a high-profile rally on Oct. 5 in Butler, the site where a gunman attempted to assassinate him in July.

On Tuesday evening, Biden will appear as the special guest at the Philadelphia City Committee’s fall dinner on Tuesday, according to sources familiar with the event. It’s a fundraiser for the city committee and comes as Democrats are trying to juice turnout in the deep-blue city. The event will be held at the Sheet Metal Workers Banquet Hall on Columbus Boulevard, with Lt. Gov. Austin Davis and Philadelphia Mayor Cherelle L. Parker expected to attend.

Also Tuesday, first lady Jill Biden will campaign for Harris in Blue Bell, Montgomery County. It’s a bit of a homecoming for Jill Biden, who grew up in Willow Grove. She’s expected to appear at Montgomery County Community College at about 6:30 p.m.

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Across the commonwealth, Walz is scheduled to hold a rally in Pittsburgh and will make two other stops in western Pa. — one in Butler County and another in Lawrence County. His wife, Gwen Walz, will also appear at events in Harrisburg, Altoona, and Pittsburgh.

Vance is headlining a town hall event in Lafayette Hill, Montgomery County, on Tuesday evening. The event is hosted by the group MomVote and will focus on issues affecting mothers and grandmothers. It’s scheduled for 6 p.m. and will be at the Union League Liberty Hill. The event is notable in that it’s in deep-blue Montgomery County just a day after a Trump rally in the area.

Harris is expected to be back in the Philadelphia area on Wednesday, traveling to Bucks County for a campaign event. It will be her 11th visit to Pennsylvania.

Vance is holding a rally in Williamsport, Lycoming County, at 3 p.m. Wednesday. It’s scheduled to take place at the Liberty Arena. The small city is in a majority Republican county in a deep-red swath of central Pennsylvania. Energy policy is likely to take center stage — gas drilling has brought major economic change to the area over the last two decades.

A Republican Voters Against Trump bus tour is stopping in Philadelphia Thursday as part of a swing state campaign funded by an outside group that says it’s spent $10 million in Pennsylvania already.

Vance will deliver remarks at a downtown Pittsburgh hotel on Thursday afternoon.

West Virginia Gov. Jim Justice, a Republican, and his famous English bulldog, Babydog, will stump for the Trump campaign in Waynesburg, Greene County, on Thursday evening.

Trump is holding a rally on Saturday in Latrobe, a small city in Westmoreland County outside Pittsburgh.

More events are likely to be scheduled for the later days this week.

Inquirer staff writers Julia Terruso and Fallon Roth contributed to this article.