It's easy to have excessive voters on the rolls in PA. Due to Motor Voter, they no longer purge the rolls of inactive voters on a frequent basis. I inquired at our precinct on Tuesday when I found my father-in-law was still registered to vote here despite moving to TN in '93. They told me that they used to remove the names of voters who failed to vote in 2 consecutive elections (including primaries). Now they are required to wait until a voter has missed two consecutive presidential elections and drop him before the 3rd election. A 12 year lag in purging inactive voters permits a lot of "voting" by people who are dead or have moved away. It also keeps their registrations active . . .
It's a mess, and very vulnerable to fraud of various types.