The figure below, produced by the CUNY Mapping Service at the Center for Urban Research, CUNY Graduate Center, shows the difference between the current 2020 Census response rate and the 2010 Census response rate. See attached document for higher resolution image. While Pennsylvania, has fewer red counties, representing differences of 10 percentage points or more, than some other states, it does have five counties that fall within this range, including: Cameron, Jefferson, Montour, Philadelphia, and Tioga.
As of the end of July, Pennsylvania ranks 17th in the nation for its current 2020 Census response rate (66.0%). The five counties with the lowest response rates in Pennsylvania include: Forest (25.9%), Sullivan (30.6%), Pike (38.4%), Cameron (41.9%), and Wayne (45.7%). Those with the highest response rates include Bucks (75.3%), Lancaster (74.7%), Chester (74.6%), Montgomery (74.0%), and Cumberland (73.5%).
For more information on response rates, visit: https://www.censushardtocountmaps2020.us/