When will Pennsylvania count mail-in ballots?

Pennsylvania voters shouldn’t look forward to election results anytime soon, with even an unofficial tally for the swing state likely off the table until Friday, according to local election officials.

Due to a crush of mail-in ballots — which, thanks to a Supreme Court ruling, can be counted up to three days after Election Day — the fate of the state’s potentially crucial 20 electoral votes will remain up in the air for some time.

Because mail-in voters predominantly skew Democratic, early returns could potentially give false hope to President...