The incredibly disappearing (super?) voter
Works out that the election yesterday had 6-7% fewer ballots cast than just last year's primary cycle. It is hard to compare different elections, but there were reasons to vote this cycle. A couple heavily contested congressional races to begin with and at least the rump of what was a competitive Republican primary for president. Overall though it was far less than half the ballots cast 4 years ago when the Pennsylvania primary was still a big deal in the Democratic race for the Democratic nomination.
That scale of decline over just a year can't be attributed to a decline in the voting age population in itself... but I tell you what is a part of it.. There is an ongoing a decline in the population in ages that make up most of the county's supervoters. Still an older voter demographic I assure you, but when it comes to voter turnout even small changes in elderly demographics gets magnified in the ballot counts. Worth looking into.
Anyway... here is the recent history in ballots cast in Allegheny County elections. In this range for sure yesterday was the single lowest ballot count.