Aggressive opposition advertising and challenges from the right appeared not enough to take down U.S. Rep. Bill Shuster, whose primary race was fueled by an infusion of cash from stakeholders in the transportation industry, where he wields power as a committee chairman.
As votes continued to be tallied Tuesday, the seven-term incumbent appeared to be staving off Art Halvorson, a retired Coast Guard officer. Franklin County alpaca farmer Travis Schooley, meanwhile was trailing well behind.
Voters' support of Mr. Shuster exemplifies a nationwide trend of Republicans moving away from ultraconservative candidates and toward more moderate candidates, said Chris Borick of Muhlenberg College, a pollster and political scientist.
"This is a year when we're seeing Republicans like Rep. Shuster hold on to their seats and fight off the types of Tea Party challenges that have, in the past, been more successful," he said.
If Mr. Shuster prevails in the final vote count, his next challenge will come from Alanna Hartzok, who ran unopposed in the Democratic primary. It will be an uphill climb for Ms. Hartzok, who hasn't raised any money and who will be running in a heavily Republican district.
Meanwhile, longtime Rep. Mike Doyle of Forest Hills -- the only other Pennsylvania incumbent with primary competition -- appeared to be sailing through a repeat challenge from fellow Democrat Janis Brooks, who runs a social service agency in North Versailles. With no Republican filing for the seat, the primary win seals Mr. Doyle's return to Washington for an 11th term.
Just to the east, Harrison businesswoman Erin McClelland defeated retired Marine Corps Col. John Hugya in the 12th District Democratic primary for a chance to unseat freshman Republican Keith Rothfus.
In a statement, Ms. McClelland said she was "honored and humbled" by the nomination.
"We have come a long way since we started on this road, but our work is not done yet," she said. "We get to keep on fighting to fix Washington, to make our government work for us and to make sure the people of Western Pennsylvania have their voices heard."
Ms. McClelland, of the Alle-Kiski Valley, operates Arche Wellness, a rehabilitation center for substance abuse and psychological issues. She has said that her 17 years of experience as a researcher and expert on behavioral health care would be an asset in crafting health policy in Congress. According to her campaign biography, she already has worked on health care policy as an adviser to the White House Office of National Drug Control Policy.
On the other side of the state, Democrat Brendan Boyle and Republican Dee Adcock, were leading the field in their respective primaries and set to face each other in November for a chance to replace Rep. Allyson Schwartz, D-Philadelphia.
Ms. Schwartz gave up her House seat to run for her party's gubernatorial nomination. She lost that contest to Tom Wolf, a businessman and former state revenue secretary.
Mr. Adcock is a businessman who campaigned on promises to work to help put the American dream within reach. Mr. Boyle is a two-term state representative. Tuesday night's win virtually assures him a seat in Congress, since the 13th is among the most Democratic leaning congressional district in the country.
Mr. Boyle's appeal to organized labor, his traditional approach to campaigning and his ability to stay out of the fray while other candidates were attacking each other helped him Tuesday, Mr. Borick said.
"He really appealed to unions, which still very much matter in Democratic politics, and he was able to leverage union support in a lower-turnout election," Mr. Borick said. "He needed that union support."
The four-way Democratic primary for that congressional seat was one of the most expensive in the country. The candidates raised a combined $4.6 million to fund their aggressive primary campaigns, according to the most recent campaign finance reports.
Like Ms. Schwartz, Rep. Jim Gerlach, R-Chester, also declined to run for another House term, but his open seat drew far less attention from either party. Republican Ryan Costello and Democrat Manan Trivedi ran unopposed in their respective primaries.
Mr. Costello is a Chester County commissioner while Mr. Trivedi is a physician and a Navy veteran.
The minimal interest in that seat and others -- including the one Mr. Rothfus only narrowly won two years ago -- baffles political scientists like Mr. Borick.
Gerrymandering made most of the districts uncompetitive in the general election, so that should raise the stakes for primaries, Mr. Borick said. In Pennsylvania, it hasn't.
"It hasn't been a very vibrant primary season," he said. "Maybe we'll see it rev up, but right now there's just not a lot of energy."
Washington bureau chief Tracie Mauriello: firstname.lastname@example.org, 703-996-9292 or on Twitter @pgPoliTweets.