MUNHALL, Pa.—In the quiet suburban sprawl of Pittsburgh is one of the most important counties on the U.S. electoral map: Allegheny County, with its population of 1.2 million.
Allegheny County is a confluence of demographics that define national politics: urban professionals, steel workers, college students, retirees, and unionized labor. Despite its Democratic lean, a shift in support here—even by a few votes—can change the outcome of Pennsylvania’s elections, which are seeing ever narrower margins.
