Philadelphia is an old story, the whole state of PA now has more registered than eligible. I think that I read that there is a law that voters cannot be removed from the voter rolls for five years.
It includes more than voter rolls. In 2000, noncitizen immigrants, many of whom could not speak English, were "assisted" in voting at the polls in Philadelphia. Local Dimwit district justices (small claims court judges) issued orders directing the poll works to allow Vlad, Sveba, et al. to vote, and the Dimwit poll workers were happy to obey these illegal orders.