Incumbent Governor Dick Thornburgh ran unopposed for the Republican nomination. Allen Ertel was the consensus Democratic choice. His opponents included Philadelphia political consultant Steve Douglas, Fayette County businessman Earl McDowell, and Northumberland County dentist Eugene Knox.
Thornburgh, who maintained high approval ratings during his first term, was initially considered a shoo-in for reelection, especially after the Democrats' top candidate, Philadelphia District Attorney (and future governor) Ed Rendell, declined to seek the nomination. Ertel struggled early with fundraising and, because of his residence in heavily Republican Central Pennsylvania, lacked a base among the state's strongest Democratic constituents: urban voters and organized labor. However, as a serious recession hit the state, Ertel campaigned hard against the economic policies of President Ronald Reagan, whom Ertel blamed for failing to protect the state's manufacturing sector; Thornburgh was forced to distance himself from his party's executive, as support for Reaganomics waned.
The state's political environment strongly favored Ertel not only because of national issues, but because the governmental cuts undertaken by Thornburgh during his term as governor had caused him to lose the support of severally traditionally Democratic-leaning organizations that had once stood by his side, such as the NAACP and the state's teachers' union. However, Ertel ran a relatively mediocre campaign and hurt his chances with several gaffes, such as accusing the governor of exploiting his handicapped son's condition for political gain. Ertel's own mistakes were considered to be a crucial component in Thornburgh's win.