At risk of being a naysayer, but statistics can be made to say pretty much what ever you want. First, what point in 2016 does the change start. Presidential years always see a swing in registration. PA was seeing an increase in GOP throughout 2016 due to Trump. A better statistic would be the change since the election or Jan. 1, 2017. Its hard to believe but the idea persists that people think they have to be registered to vote in the party of the candidate they want to vote for, thus was the case in PA during 2016 and the case for the imposter in 2008. Second, why do we have a RAT governor and lost house seats in NC if the NET increase has been that much? That change is HUGE and would have twice the effect of the same change in the bigger state of FL and, to a lesser extent, PA.
I recently changed my registration from Independent to Republican. Pa. is a closed primary election state so if I remained an Independent I would not be able to vote in the Republican primary in 2020. President Trump will need my vote...