The endorsed candidates for the two major parties each won by large margins, with Duff earning over three-quarters of the vote against outgoing Secretary of Highways John Shroyer of Shamokin and Rice winning by a similar margin over Mahanoy City businessman Henry Morris.
Pennsylvania gubernatorial Democratic primary election, 1946
A close confidant of popular outgoing Governor Ed Martin, who was running for a US Senate seat, Duff was the clear favorite throughout the campaign. Duff ran as a moderate progressive but also as a hardline anti-communist. He promised to address the key topic of labor strife by limiting strikes and cracking down on union criminal activity while concurrently increasing the minimum wage. Duff also vowed to spur innovation amongst the state's fragmented local governments.