Was there actually a good reason for this? The limitation seems completely arbitrary or stems for a misunderstanding about the difference between a state and a

Was there actually a good reason for this? The limitation seems completely arbitrary or stems for a misunderstanding about the difference between a state and a territory. For better or for worse, Puerto Rico is virtually a state (with residents who can't vote for the president with some minor other caveats), but legally there shouldn't be any difference.