Republican departures have helped the minority party. In three important races in the state, a GOP incumbent has either resigned or announced his intention to retire.
Several House districts in Pennsylvania will feature competitive races either on Tuesday, in November or both.
- PA 1st District: Democrats are vying to face GOP Rep. Brian Fitzpatrick in a district that shifted in favor of Democrats under the revised map. In 2016, Hillary Clinton narrowly won the new district. Multimillionaire philanthropist Scott Wallace, a former counsel for Senate committees, has piled $2.5 million of his own money into the Democratic primary. The other leading contender is former Navy prosecutor Rachel Reddick. She is endorsed by Emily's List, the organization that aims to elect pro-choice Democrats. On the Republican side, Fitzpatrick faces one challenger in lawyer Dean Malik. The congressman is expected to win. Nonpartisan election handicappers rate the November race as a toss-up.
- PA 5th District: The state's redistricting made the 5th District dramatically more Democratic. Cook Political Report's Partisan Voter Index, or PVI, which gauges how areas vote in recent presidential elections relative to the country as a whole, now lists it as "D+13." The seat is currently vacant, as Republican Rep. Pat Meehan resigned after the revelation that he used taxpayer money to settle a sexual harassment claim made by a former staffer. Ten Democrats will jostle for the nomination Tuesday. Whoever wins the primary will become the heavy favorite to win the House seat in November. Top contenders include attorney Mary Gay Scanlon, former Philadelphia Deputy Mayor Richard Lazer and former federal prosecutor Ashley Lunkenheimer. Pearl Kim, a former prosecutor in the Pennsylvania Attorney General's office, is the lone Republican candidate.
- PA 7th District: Democrats got two breaks in the 7th District congressional race. First, redistricting made the area more favorable. By Cook's PVI, it is now a "D+1" district. Then, incumbent GOP Rep. Charlie Dent resigned. While the seat became more competitive for the party, discord could complicate the Democrats' chances. Northampton County District Attorney John Morganelli, a leading Democratic contender, opposes abortion rights and has praised President Donald Trump in the past. He faces pastor Greg Edwards, a candidate running from the left endorsed by Sen. Bernie Sanders, I-Vt. Former Allentown Solicitor Susan Wild, backed by Emily's List, is also vying for the nomination. Former Lehigh County Commissioner Dean Browning and former Olympic cyclist Marty Nothstein are running on the Republican side.
Others to watch: The primary elections in Pennsylvania's 6th and 17th Districts may not carry much drama. But the races for those seats in November will be critical. GOP Rep. Ryan Costello declined to run for re-election in the 6th District, now a "D+2" seat, according to Cook. Chrissy Houlahan, a businesswoman who served in the Air Force Reserve, runs unopposed on the Democratic side. Attorney Greg McCauley faces no opponents in the Republican primary. Houlahan would enter the general election as a favorite.
The 17th District features a rarity in congressional elections: two incumbents. Democratic Rep. Conor Lamb won a March special election for the state's previous 18th District but lives in the revised 17th District. Both he and GOP Rep. Keith Rothfus will run unopposed in Tuesday's primaries. Cook rates it as an "R+3" seat — less red than the area Lamb won in March.
Read more: Long-distance donors flood Tuesday's Pennsylvania primaries with cash