Pennsylvania's 10th congressional district

Pennsylvania's 10th congressional district is currently located in the south-central region of the state. It encompasses all of Dauphin County as well as parts of Cumberland County and York County. The district includes the cities of Harrisburg and York. Prior to 2019, the district was located in the northeastern part of the state. The Supreme Court of Pennsylvania redrew the district in 2018 after ruling the previous map unconstitutional because of gerrymandering. The court added State College to the old district's boundaries while removing some Democratic-leaning areas and redesignated it the twelfth district; an area encompassing Harrisburg and York was numbered as the "10th". The new tenth district is represented by Republican Scott Perry, who previously represented the old fourth district.

The district was one of the 12 original districts created prior to the 4th Congress. In 2006, when it was still located in northeastern Pennsylvania, the 10th district experienced one of the greatest party shifts among all House seats that switched party control: in 2004, Republican Don Sherwood won with an 86% margin of victory over his nearest opponent and two years later, Democrat Chris Carney unseated Sherwood by a 53%–47% margin. In 2008, Carney won reelection by 12 points but the district swung back in 2010, electing Republican Tom Marino. The district was mostly Republican in its political composition, an aspect of the district that was reflected especially well in presidential elections. In 2004, President George W. Bush won 60 percent of the vote in the district and in 2008, Senator John McCain beat Senator Barack Obama here by a margin of 54 percent to 45 percent. Nonetheless, Carney easily won reelection as a Democrat the same year McCain won the district. However, in the 2010 midterm elections, Marino unseated Carney by a 55%–45% margin. In 2016, local businessman and former mayor of Lewisburg, Mike Molesevich challenged Marino for the seat, but he fell to the Republican in November by more than two to one. In 2018, Marino won election to a redrawn 12th district; while he remained the congressman for the 10th district into January 2019, he moved within the new district's boundaries beforehand.

Demographics
According to the APM Research Lab's Voter Profile Tools (featuring the U.S. Census Bureau's 2019 American Community Survey), the district contained about 559,000 potential voters (citizens, age 18+). Of these, 80% are White, 10% Black, and 6% Latino. Immigrants make up 5% of the district's potential voters. Median income among households (with one or more potential voter) in the district is about $67,300, while 9% of households live below the poverty line. As for the educational attainment of potential voters in the district, 9% of those 25 and older have not earned a high school diploma, while 30% hold a bachelor's or higher degree.

District boundaries 2003–2013
The Pennsylvania 10th was the third-largest congressional district in the state. The district encompassed the following counties and areas:


 * Bradford County
 * Lackawanna County
 * excluding Old Forge, Moosic, Scranton, and Dunmore but including Clarks Summit
 * Luzerne County
 * Back Mountain area, including Dallas, Shavertown, Trucksville, Kingston, Wyoming, and Swoyersville
 * Lycoming County
 * Sullivan/Columbia/Montour County boundaries west to the West Branch of the Susquehanna River (except Montoursville), north to Cogan House
 * Montour County
 * Northumberland County
 * Pike County
 * Snyder County
 * Sullivan County
 * Susquehanna County
 * Tioga County
 * Ward Township
 * Union County
 * Wayne County
 * Wyoming County

District boundaries 2013–2019
On June 8, 2012, The Pennsylvania Legislative Reapportionment Commission adopted a revised final redistricting plan. On May 8, 2013, The state Supreme Court unanimously approved the Legislative Reapportionment Commission's 2012 Revised Final Plan. The resulting district encompassed the following areas:
 * Bradford County
 * Juniata County
 * Parts of Lackawanna County
 * Including: Abington Township, Benton Township, Ransom, Newton, South Abington, Clarks Summit, Clarks Green, Glenburn, West Abington, Dalton, La Plume, North Abington, Scott, Greenfield, Fell, Vandling, Jefferson, Olyphant, Madison, Covington, Clifton, Moscow, Elmhurst, Roaring Brook, parts of Carbondale, and parts of Archbald.
 * Lycoming County
 * Mifflin County
 * Parts of Monroe County
 * Including: Barrett, East Stroudsburg, Jackson, Mount Pocono, Paradise, Pocono, Price, Stroudsburg, and parts of Stroud.
 * Parts of Northumberland County
 * Including: Delaware, East Chillisquaque, West Chillisquaque, Watsontown, Lewis, Turbotville, Turbot, Milton, Point, Northumberland
 * Parts of Perry County
 * Including: Toboyne, Jackson, Blain, Northeast Madison, Southwest Madison, Landisburg, Tyrone, Saville, Centre, New Bloomfield, Tuscarora, Juniata, Greenwood, Millerstown, Oliver, Newport, Miller, Howe, Liverpool Township, Liverpool, Buffalo, Watts, and New Buffalo.
 * Pike County
 * Snyder County
 * Sullivan County
 * Susquehanna County
 * Majority of Tioga County
 * With the exception of Clymer Township, Chatham Township, Gaines Township, and the majority of Shippen Township
 * Union County
 * Wayne County

List of members representing the district
District created in 1795.

2016 election
Rep. Tom Marino declared his intent to run for his 4th term and was uncontested in the Republican primary. Originally, no Democratic candidates filed to run for office, upon this revelation, Mike Molesevich, an environmental contractor and former Lewisburg mayor, announced he would seek a write-in campaign to get on the general election ballot. Write-in candidates need over 1,000 votes in the primary election to appear on the ballot in the 2016 general election. Mike Molesevich succeeded in his effort, receiving 2425 votes, earning a spot on the general election ballot. Jerry Kairnes of Lycoming County announced that he would seek to be on the November ballot as an Independent, but dropped out after Molesevich earned a spot on the ballot

2024 election
Among the Democrats who have announced their intentions to challenge Perry are Pennsylvania businessman John Broadhurst, WITF senior vice president and director of community policing for the Harrisburg Bureau of Police Blake Lynch, former WGAL-TV anchor Janelle Stelson, retired Marine Mike O'Brien, retired soldier Rick Coplen, and Harrisburg city councilor Shamaine Daniels.