Voters are also heading to the polls Tuesday in Idaho, Nebraska and Oregon.
18 congressional races and a U.S. Senate main.
That's not exactly a huge margin for Barletta, a longtime congressman who had the explicit endorsement of the President - and who spent almost $2 million on the race to just $250,000 for Christiana.
Republicans, meanwhile, see Casey's seat as freshly vulnerable, and Barletta has made a point of portraying Casey as soft on immigration, oppositional toward the president and a lackluster working-class advocate, hoping these points will resonate with voters in a state that Donald Trump won less than two years ago.
Barletta was a Trump supporter before the 2016 presidential nomination was settled.
Trump edged Democrat Hillary Clinton by less than 1 percentage point in Pennsylvania in 2016's presidential election.
The GOP holds a razor-thin 51-to-49 advantage, but leaders are increasingly bullish about adding to their majority as Trump's approval ratings have ticked up.
Saccone lost Tuesday's 14th Congressional District primary election to state Sen. Fischer's race was called at 9:30 p.m. The forty-fifth president also noted Barletta's support for pro-American immigration reform as well as his vote for the recently passed Tax Cuts and Jobs Act. Scott Wagner defeated businessman and Army veteran Paul Mango for the chance to face off in November against Democratic Gov. Tom Wolf, who ran unopposed.
Farther west in OR, incumbent Democratic Gov. Kate Brown drew a pair of primary challengers but was expected to advance to the general election. He ran against nonprofit executive Kara Eastman.
In Idaho, Rep. Raul Labrador - an influential member of the House Freedom Caucus - is one of three front-runners in a crowded gubernatorial primary.
Barletta and Republicans like him across the country are taking a different tack than Democrats did in 2014 when, aware that the president's party tends to lose seats in midterms, they distanced themselves from Barack Obama.
Nebraska Republican Gov. Pete Ricketts faced a primary challenger, but he was favored to win his party's nod, as well as a second term in November.
But she faces a hard race: Idaho hasn't elected a Democratic governor since 1990, and the Republican Party now controls a supermajority on all federal, state and legislative seats.