Net Shift in Pa. Voter Registrations, 2016 to 2020
Between the 2016 and 2020 primary elections, Democratic voter registrations increased by 30,506, or 0.7%, while Republican voter registrations increased by 164,778, or 5.2%.
Net shift is the difference between the changes in Democratic and Republican registrations. For example, a county that added 100 Democrats and 120 Republicans would have a +20 Republican shift; a county that added 100 Democrats and lost 120 Republicans would have a +220 Democratic shift.
Source:Inquirer analysis by JONATHAN LAI of data from Pennsylvania Department of State