Region Comment
The objective of this region was to put together all of the major cities and metropolitan areas to the northeast of Philadelphia. This included Leigh Valley, Wyoming Valley, Harrisburg, Reading and Lancaster. The only areas that I did not have from for that should probably be in this region is York and the western Harrisburg suburbs. Both Bob Casey and Pat Toomey are from this region, so this could be an incumbent vs. incumbent battle, but I could also see either moving to a safer Pennsylvania region.
I'd put York and the rest of the Harrisburg metro in there, exchanging with Scranton. Scranton/Wilkes-Barre belong with the NY southern tier/PA northern tier much more than York does. Similarly I'd put Erie in with those tiers; you can send Pittsburgh east rather than north.