In tonight's primaries, voters aren't just deciding on federal candidates for November's general election; they're also setting up the battles for control of the state House and Senate. In 2022, Democrats won the governorship, and they currently hold a one-vote majority in the House they've struggled to maintain through a series of special elections. The party is looking to expand that House majority and gain control of the Senate for a trifecta by targeting opportunities (and defending some vulnerable seats) in the purple areas of this purple state. And, of course, Republicans want to keep their Senate majority, which they've held for 30 years, and take back the House.

Republicans have a six-vote majority in the state Senate, so Democrats need to pick up at least three seats for a tie, which could be broken by Democratic Lt. Gov. Austin Davis. Half the chamber is up for election this cycle. Among the handful of key races, Democrats will be defending an Allegheny County seat and challenging Republicans for a Harrisburg-based seat that are both opening up because of retirements. In both districts, each party is holding a contested primary today and redistricting could give Democrats a boost in November. Democrats are also challenging Republican incumbents in two seats that flipped to red in 2016 and 2020; one will hold a competitive Democratic primary today between Erie County Democratic Party Chair Jim Wertz and former Sen. John Fetterman staffer Selena King.

In the House, the hot primary action will largely be on the Democratic side, as the party's more progressive and centrist flanks face off in districts around Philadelphia and Pittsburgh. In West Philadelphia, Rep. Amen Brown is defending his seat against two challengers, Sajda Blackwell, whose family has a history in area politics, and progressive community activist Cass Green. Brown ran unsuccessfully for mayor on a tough-on-crime stance, and has sided with Republicans in criticizing progressive Philly DA Larry Krasner. Elsewhere in the city, three incumbents endorsed by progressive group Reclaim Philadelphia are facing challengers of their own. And in the Pittsburgh area, state Rep. Abigail Salisbury, who stepped into U.S. Rep. Summer Lee's former seat, is facing a challenge from Ashley Comans, a progressive school board member who lost to Salisbury last year and is endorsed by Lee herself.

Tonight's results will have an effect on their party's chances to hold onto the state House majority in November, and also the direction the Democratic party may try to take should it seize a trifecta.

—Monica Potts, 538

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

The war between Israel and Hamas in Gaza has paved the way for some bitter Democratic primary fights in 2024. Among those most critical of Israel's actions in the conflict has been The Squad, an informal group of around nine progressive Democrats who often clash with their party's establishment. Of that cohort, Rep. Summer Lee of Pittsburgh is the first to face a contested primary in 2024 — but she won't be the last. At least four members, including Lee, have potentially significant primary opposition in part because of their vocal denouncements of Israel — although increasingly negative views of the Middle East nation's actions among the Democratic base means the conflict may not be as helpful to The Squad's challengers as some may have expected.

Should Lee survive, she would join Reps. Greg Casar of Texas and Delia Ramirez of Illinois among those who've won renomination (Casar and Ramirez faced no opposition in their March primaries). But some members with primaries later this summer may have problems, especially the two who are arguably most endangered: New York Rep. Jamaal Bowman and Missouri Rep. Cori Bush. For one thing, they've each been outraised by their leading challengers, and they both have potential scandals that could derail their reelection efforts. Last fall, Bowman pulled a fire alarm in a Capitol office building right before a vote, which resulted in him paying a fine and receiving a censure from the House. And Bush faces investigations by the Department of Justice, Federal Election Commission and House Ethics Committee into alleged misuse of funds to pay her security team, including payments to her husband as part of that team.

Beyond those two, Minnesota Rep. Ilhan Omar may be the other Squad member who could have some trouble. Two years ago, she defeated former Minneapolis City Council member Don Samuels by just 2 percentage points in the Democratic primary; now Samuels is back for a rematch, although Omar has already raised more than twice as much as the $2.4 million she'd brought in by the time of the 2022 primary>. Otherwise, there are few signs that New York Rep. Alexandria Ocasio-Cortez, Michigan Rep. Rashida Tlaib and Massachusetts Rep. Ayanna Pressley will have difficulties. Ocasio-Cortez does have a challenger, but his largely self-funded effort pales in comparison to Ocasio-Cortez's campaign war chest, while Tlaib's little-known opponents only just filed for the race and haven't reported raising any money. Pressley, meanwhile, has no primary opposition ahead of Massachusetts's May 7 candidate filing deadline.

—Geoffrey Skelley, 538