They can and they do. There are over 3,000,000 living in the contiguous States.
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.
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 :)
For employment opportunity.
Yes, they can.
US citizenship
Many are.
All Puerto Ricans are US Citizen since 1917. Saying How PRicans arrive to the US is like saying how Californians arrive to Texas. From Puerto Rico you will have to take a plane to get to US Continental