The Democrats

With strong support from organized labor, Hubert Humphrey won Pennsylvania's primary, his first victory in the 1972 Democratic primaries. Organized labor helped Humphrey win the mining and milling town areas of western Pennsylvania; he won every county west of the Susquehanna River, except for Centre and Union (See Map below). Humphrey's victory was geographically broad based. With the exception of the southeastern counties that surrounded Philadelphia and the northeast, he won every region of the state. Philadelphia's suburban counties went for McGovern. Humphrey won 481,900 popular votes, or 35% of the total. Wallace won 292,137, or 21% of the vote; McGovern won 280,861, or 20% of the vote; Muskie won 279,983, or 20% of the vote; Henry Jackson won 38,767, or 3%.

The Republicans
The Republican nomination for president in 1972 was a virtual lock for incumbent President Richard Nixon. Nixon faced only minor challenges from the conservative wing of his party in the candidacy of John M. Ashbrook of Ohio and from the liberal wing of his party in the candidacy of California Congressman Paul N. McClosky, a liberal Republican, anti-Vietnam war opponent. Still, no Republicans other than Nixon filed in Pennsylvania's presidential preference poll.