Vice President Kamala Harris holds a 5-point lead over Donald Trump in a Pennsylvania congressional district he carried four years earlier, according to a poll.

Pennsylvania, roughly evenly divided between Democrats and Republicans, is among the most important battlegrounds of the presidential race. It has flipped between Democrats and Republicans in the past few elections, and Harris and Trump are essentially tied there.

Political experts view it as a must-win state for Harris, as her easiest path to 270 Electoral College votes may be sweeping the Rust Belt swing states. Polls point to a close race in the Keystone State, with FiveThirtyEight’s polling aggregate showing her up only 0.4 points over the former president.

A new survey from Susquehanna Polling & Research showed Harris with a slight lead in Pennsylvania’s 10th Congressional District, a traditionally Republican-leaning district, the polling company said Wednesday on X (formerly Twitter).

The poll showed Harris up in the district by 5 points (46 percent to 41 percent).

The district covers Harrisburg and its suburbs, as well as York. The Harrisburg area has shifted toward Democrats in recent years, with the party making gains in more suburban areas. But it still went for Trump by 4 percentage points in 2020 (51 percent to 47 percent), according to data from Daily Kos.

Susquehanna CEO James Lee told Newsweek that Democrats typically do well in Harrisburg but Harris is also pulling stronger numbers in suburban Cumberland and rural York, which may be concerning for Trump.

“The fact that Harris is even this competitive in the district is certainly something that would raise alarm bells for the Trump campaign,” he said.

Trump is likely to still win the region, known as South Central Pennsylvania, but a weaker performance in the 10th district could be a “drag” on his state numbers, Lee said. The district is a must-win for Trump, as his numbers in Allegheny County, home to Pittsburgh, and the Philadelphia suburbs aren’t likely to make up for a loss in the 10th congressional District.

GOP Representative Scott Perry, a former chair of the House Freedom Caucus, represents the district. He is facing a challenge from Democrat Janelle Stelson. The Cook Political Report classifies the race as “Leans Republican,” meaning it is considered competitive but Perry has an advantage.

The poll had Stelson, a former local news anchor, leading Perry by 9 points.

“If this seat flips to the Democrats, you’re talking about the potential for this to be quite consequential in terms of the U.S. Congress,” Lee said, as only a handful of GOP-held seats need to flip to Democrats for control of the House to change.

Kush Desai, the Trump campaign’s spokesperson for Pennsylvania, told Newsweek on Wednesday that “pollsters, the media and ‘intellectuals’ have repeatedly failed to grasp the depth and breadth of support for President Donald J. Trump from the American people.”

Desai added: “The Commonwealth of Pennsylvania is going to prove itself, once again, to be Trump country in November.”

Jacob Rubashkin, the deputy editor for the newsletter Inside Elections, wrote on X that the poll may be an “outlier.”

“This would be an outlier even among the Democratic polling we’ve seen in the district — not a bad thing, outliers should happen and they’re useful data points — but important context,” he wrote.

Newsweek reached out by email to the Harris campaign for comment.

The poll surveyed 300 voters in the district from October 4 to 7 and has a margin of error of plus or minus 5.6 percentage points.

Susquehanna is seen as a reliable Pennsylvania pollster, with its polls pointing to a close race and being only a few points off in 2016 and 2020.

In 2020, its final poll showed Trump leading President Joe Biden in Pennsylvania by about a single percentage point (49 percent to 48 percent). Biden ultimately won the state by just over a single point (50 percent to 48.8 percent).

In 2016, its final poll showed Hillary Clinton with a 2-point lead (45 percent to 43 percent). Trump ultimately won Pennsylvania by less than a single point (48.2 percent to 47.5 percent).