Pennsylvania is a gerrymandered swing state that both parties have carried in recent statewide elections. In 2018, Democrats held the governor’s seat, gained 5 seats in the state Senate and 11 in the House. 


How Redistricting Happened in Pennsylvania

The following timeline is a high-level overview outlining major redistricting events and activity in the state of Pennsylvania over the last 10 years.


Republicans gained control of the governorship and won trifecta control of the state, meaning that Republicans controlled the governorship and both chambers of the state legislature.


Census data delivered to Pennsylvania.

Republican-controlled legislature approved gerrymandered congressional map that Republican Governor Tom Corbett subsequently signed into law.

Politician-led redistricting commission issued and approved state legislative map.


The Pennsylvania Supreme Court struck down the legislative map because it violated the Pennsylvania Constitution’s redistricting criteria and ordered a new map.

President Barack Obama won Pennsylvania with 52% of the vote and Democrat Bob Casey Jr. won a U.S. Senate seat with 54% of the vote, but gerrymandered maps gave Republicans 72% of the congressional delegation and 54% of the state Senate and state House.


The Pennsylvania Supreme Court approved the commission’s revised state redistricting plan.


Democratic Governor Tom Wolf won the governor’s seat by an almost 10-point margin with 55% of the state vote, but gerrymandered maps helped Republicans gain more seats in both the state Senate and House.


Republicans won a supermajority in the state Senate, even though the state split almost evenly between Donald Trump and Hillary Clinton.


The Pennsylvania Supreme Court struck down the congressional map as a partisan gerrymander in violation of the state’s Constitution and ordered the state legislature to produce a new map.

The legislature drew another gerrymandered map that Governor Wolf did not approve.

A special master appointed by the state Supreme Court produced a fair map that will be in effect for the midterm elections this year.

Pennsylvanivoters elected Government Wolf again and elected more Democrats to the state legislature.

Know the Races that Impact Redistricting

1 Know the Decision Makers

Congressional map lines are drawn by the state legislature and approved by the governor. State legislative map lines are drawn by a 5-member commission, chosen by the following four elected officials:

  • State Senate Majority Leader
  • State Senate Minority Leader
  • State Speaker of the House
  • State House Minority Leader

2 Know Your State Legislature

Pennsylvania Lower Chamber




Pennsylvania Upper Chamber




1 Vacant seats

4 Vote

Court Cases Impacting Pennsylvania

The League of Women Voters of Pennsylvania and individual voters successfully challenged the congressional map passed earlier this decade for violating the Pennsylvania Constitution. A new map is in place for this year’s midterm elections.

League of Women Voters of Pennsylvania v. Commonwealth of Pennsylvania

Read the Pennsylvania Supreme Court majority opinion.

Get Involved in Pennsylvania Today

The fight to fix gerrymandering is right now—and we need your help in Pennsylvania! Here’s what you can do:

Join Organizing for ‘18

The National Democratic Redistricting Committee and Organizing for Action launched a partnership to build a more fair democracy by strategically targeting legislative chambers, governorships, and ballot initiatives that will be critical in determining how maps are drawn after the 2020 Census.

Join a Local OFA Chapter

Alongside the National Redistricting Action Fund (an NDRC affiliate), OFA is engaging with activists and volunteers to help educate people about gerrymandering and involve them in the process of fixing a badly rigged political system.

Attend Events Near You

The National Democratic Redistricting Committee and MobilizeAmerica have teamed up to bring you the highest-impact volunteer opportunities in Pennsylvania to help elect Democrats up and down the ticket — and bring an end to Republican gerrymandering.

You can register to vote for the general election in Pennsylvania up until .

to Vote