For the same reason that some one from New York who moves to California is not Considered an immigrant. Puerto Rico is part of the United States. Puerto Ricans are US citizens by birth since 1917.
If you were asking "Are Puerto Ricans illegal aliens?" that would be a yes AND no answer. Puerto Ricans are considered immigrants because Puerto Rico is not part of the United States (its not one of our 50 states), but it is US territory (we protect them and stuff). :) hope this helped you :)
if you were born in Puerto Rico and live in the US. YES, YOU CAN VOTE.
The 1917 Jones Act designated Puerto Ricans as US Citizens.
Citizens.
Between two and three million that are self identified as Puerto Ricans.
They are US Citizens.
All puerto ricans are us citizen since 1917 and if they live in the states they have to to pay federal taxes.
US citizenship
For employment opportunity.
Yes, they can.
Yes because the US owns Puerto Rico. But Puerto Ricans would refer to themselves as Puerto Ricans more than American, just like English would consider them more English than British.