In 2020, Philadelphia, PA -> NJ, Chatham, GA (Savannah) -> SC, and Coconino, AZ (Grand Canyon area) -> UT elects Trump.
I recall that Florida Panhandle -> Alabama and UP of Michigan -> Wisconsin is enough to elect Clinton in 2016.
She wins the Electoral College if you give Camden County (NJ) to Pennsylvania, Monroe County (MI) to Ohio and Lake County (IL) to Wisconsin.
Oh wow, so you can also change 2016 with 3 urban counties! I was too hung up on Cook flipping IN by itself to think of the suburb counties.
