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