There were three candidates from Montco and one from Philly. The Philly guy won with the least amount of money but with very strong union support. He also was tepidly pro-life (while claiming to support Roe) so that gave him an advantage with Catholic Dems. The outgoing incumbent, Allyson Schwartz who tried and failed to gain the Dem gov nomination, was a pro-abort ghoul so this was the first contested Dem primary in some time with a marginally pro-life candidate, and the three Montco Dems tried to bash Boyle's abortion stance, and IMO it backfired on them.
Thanks for the great details!