为什么美国领土不允许在美国总统选举中投票？

Why cannot residents from United States territories such as the CNMI, Guam, and Puerto Rico vote in general elections? (They can, however, participate in presidential primaries.) It seems unconstitutional because residents from these places are also United States citizens and should be granted the right to cast their ballot for the next President of the United States just like everyone else in the fifty states.Why cannot residents from United States territo