What do the Federalist Papers say about it?
Federalist papers are not policy, nor are they law.
It’s better to stick with the law. For the record, though, Jefferson in the Declaration said that it was the “PEOPLE” of the united colonies, not the “colonies” that declared their independence. So there’s that.
All in all, the elector system was pretty brilliant, and interesting that the Founders did not put in a “faithless elector” clause themselves.