United States presidential election in Pennsylvania, 2004

By voting for Senator John F. Kerry, Pennsylvania was the only major swing state of three to choose the Democratic opponent (Ohio and Florida, the other two extremely pivotal states, both went for Bush.) Kerry won only 12 of the 67 counties in Pennsylvania, but these 12 counties have the highest populations in the commonwealth. This Kerry victory can be attributed to the overwhelmingly Democratic cities of Philadelphia, Pittsburgh, and Erie. While it should be noted that smaller Kerry-held cities which voted for the Senator by narrow margins assisted him in advancing his margin over President Bush, many political anaylsts underscored the fact that if Philadelphia were excluded, President George W. Bush would have won Pennsylvania by a fairly slim margin, with 2,663,748 versus 2,395,890 for Kerry. Interestingly, though Pennsylvania is closely divided in most elections, it has not voted Republican in a Presidential election since 1988.

Philadelphia and Pittsburgh were the biggest contributors to Kerry's victory in Pennsylvania. However, many liberal Republicans in suburban Philadelphia counties (Bucks, Delaware, Montgomery, and somewhat in Chester) voted for Kerry, which may well have been the deciding factor. Kerry also had narrow margins of victory around cities like Allentown, Scranton, Erie, and the traditionally Democratic Pittsburgh suburbs; he also garnered many votes in certain rural areas such as parts of the Poconos and the Laurel Highlands, and in cities like Reading, Johnstown, Harrisburg, and State College. Bush's margins were extremely large in Central Pennsylvania and the sparsely populated Northern Tier, with traditional GOP cities such as Lancaster, Lebanon, York, Altoona, Huntingdon, and Williamsport strongly throwing their support behind him. This area, along with rural Western Maryland, was clearly the most conservative in the Northeast.

Statewide winner in bold. "See main article : U.S. presidential election, 2004."

Results by county