Temple is literally in Philly. Academics are similar to Mason.
Rutgers is another good choice, fairly easy to get to NY (in the burbs, about an hour train ride) and not too hard to get to Philly (about an hour and a half train ride). Academics are better than Mason or Temple, and they have a well regarded history program. There is a bus that runs between DC and NY for very cheap and there are probably others for different cities. There are fairly fast trains running to Boston and Providence from NY.
I think Rutgers is your best bet for balance between academics and location. Being near DC is overrated for the election. You’d be better off in Ohio, that’s where the real action is.