In the Harrisburg-based 10th District, Republican Rep. Scott Perry won reelection by a little less than 8 percentage points in 2022. But he remains a target for Democrats, thanks to the district's potential competitiveness and Perry's reputation as an archconservative. A crowd of six contenders have entered the Democratic primary to earn the right to face Perry in November, and there's some degree of uncertainty about how this primary might play out.

If there's a front-runner, it's probably former news anchor Janelle Stelson, whose long tenure at WGAL in the Harrisburg-Lancaster-Lebanon-York TV market has made her a familiar face in the region. Stelson had raised $577,000 as of April 3, and she has endorsements from EMILY's List and the business-friendly New Democratic Action Fund. However, Stelson has competition in retired Marine fighter pilot Mike O'Brien, who has slightly outraised Stelson by bringing in $736,000. The other candidate of note is Harrisburg City Council member Shamaine Daniels, the party's 2022 nominee against Perry, although she's only raised $73,000.

But both Stelson and O'Brien have faced questions about their ties to the district, as Stelson lives just outside it in Lancaster County and O'Brien only recently moved to the area. Stelson has also faced scrutiny for having only recently switched her party registration from Republican to Democrat and for having made a racist joke on air around a decade ago involving Asians eating cats. Whether that's enough to derail her remains to be seen: The only recent poll we've seen was a late February survey for Stelson's campaign by Normington, Petts & Associates that found her leading with 36 percent, followed by Daniels at 16 percent and O'Brien at 9 percent.

—Geoffrey Skelley, 538

Pennsylvania is one of several critical swing states with a U.S. Senate election this November. While neither party's primary is contested today, we're going to be hearing a lot about this contest, which will help determine who controls the chamber. Unsurprisingly, Pennsylvania voters are fairly evenly divided when it comes to which party they'd rather see in control, but nearly one in five don't seem to see much of a difference. Asked in a CNN/SSRS survey in March whether they thought the nation would be better or worse off if Republicans won control of the chamber, 38 percent of registered voters said they thought it would be better off and 42 percent thought it would be worse off. Nineteen percent said it will not make any difference.

—Mary Radcliffe, 538

Pennsylvanians will technically pick their nominees today for the state's U.S. Senate election this fall, though the results won't be a nail-biter — both major party candidates are running unopposed in their primaries. Democratic Sen. Bob Casey Jr. is running for a fourth term, while David McCormick, a former hedge fund CEO and diplomat under the Bush administration, is hoping to claim the seat for Republicans.

While today's primary isn't competitive, the general election matchup is already attracting a lot of attention. Democrats currently have just a one-seat majority in the Senate and are defending at least seven competitive seats this cycle, including Casey's in Pennsylvania. That means control of the chamber could come down to the Keystone State, a prospect that both parties are taking seriously.

Both candidates have already dropped millions of dollars on the race. While McCormick slightly outraised his opponent last quarter, Casey has spent over two and a half times as much money this cycle and has close to twice as much cash on hand as McCormick.

Casey also leads in every poll we've collected of the race, although some of those leads are within the margin of error. All the major election handicappers agree that he appears to have an edge in the race for now, though it's still competitive enough that things could easily change by November. Tonight won't be able to tell us much about the future, but it marks the official start to one of the most closely watched matchups this cycle.

—Cooper Burton, 538

Reporting live from the 12th District, there have definitely been some shenanigans playing out here in the Lee-Patel race, Geoffrey, so I'll be interested to see what happens with the other Squad challenges. For example, the 14th Ward Independent Democratic Club, an influential progressive group located on the East End in Pittsburgh, endorsed Patel over Lee. In 2022, the IDC endorsed Lee over the more moderate Steve Irwin, so it may look like the club has had a change of heart.

However, there's much more happening behind the scenes. Allegheny County's 14th Ward includes Squirrel Hill, traditionally the home of Pittsburgh's orthodox Jewish community. In January of this year, over 150 new members became a part of the IDC in advance of their annual votes on board members and endorsements, growing the club's membership by more than 50 percent. The new IDC members ousted board members that they considered too pro-Palestine, and were instrumental in directing the group's endorsements. So while it may appear to voters that a progressive group is abandoning Lee, a peek behind the curtain reveals quite a bit more is going on.

—Mary Radcliffe, 538

In Bucks County, just outside Philadelphia, steadfast moderate Republican Rep. Brian Fitzpatrick is facing a primary challenge from the right for his seat in the 1st District. Mark Houck is an anti-abortion activist and head of a nonprofit ministry group for Catholic men who made a name for himself as a bit of an anti-abortion martyr when he was charged with assault (but found not guilty) after shoving a 72-year-old clinic volunteer in 2021 while protesting outside a Planned Parenthood in Philadelphia. Fitzpatrick was first elected to Congress in 2016, succeeding his brother (the late former Rep. Mike Fitzpatrick). He's faced a primary challenger in every election since, but has always triumphed.

Fitzpatrick has made a reputation for himself locally and on the Hill as a moderate who keeps his distance from the MAGA right. He's got a track record of bipartisanship and moderate policy stances in Congress and refused to endorse Doug Mastriano, the GOP's far-right nominee for governor in 2022. He even snubbed Trump's visit to Bucks County earlier this month. His position on abortion has been a bit less clear — there's no mention of abortion on his reelection campaign website — though he has drawn ire from abortion rights groups. He's certainly no culture warrior like Houck, whose organization opposes "same-sex attraction disorders" and pornography, and works to shut down "sexually oriented businesses."

But whoever wins this primary isn't necessarily a shoe-in for the seat. Fitzpatrick or Houck will be going up against Democrat Ashley Ehasz. Fitzpatrick defeated Ehasz in 2022 by 10 percentage points, but the area is purple and shows signs of shifting blue — Biden won the district in 2020, and Democrats swept all five seats up for grabs in a recent local school board election. Fitzpatrick is the lone Republican in the districts surrounding Philadelphia, though his is the whitest of those collar counties and the conservative areas of the county are increasingly polarized. That could mean Fitzpatrick faces serious competition from Houck in the party primary, but Houck's far-right leanings could tilt the general election contest toward Democrats if he makes the ballot in November.

—Kaleigh Rogers, 538