Alaska and Hawaii made it pretty easy during the Cold War(1959). I don't see any reason to impose a more difficult standard for Puerto Rico. Especially since Puerto Rico's population (3.58 million) exceeds that of Alaska (634 thousand) and Hawaii (1.22 million) combined.
IMHO, it's strictly up to the Puerto Rican people to decide.
They've already proved their worthiness.
And how exactly have they done that? By attacking our Marines? By protesting the use of our military base? By leeching billions of our tax-payer dollars? With their miserable one-crop agricultural economy? With their huge percentage of welfare families? With their special exemption from paying any taxes?
Just because there are some honorable and hard-working people in some nation or territory does NOT mean that we are responsible for for their upkeep, nor does it give them the opportunity to vote themselves into our nation.
It's curious how the opinions of 300 million Americans don't seem to matter much to you, only the opinions of 50%+1 of those responsding to a statehood vote on some impoverished island. As you can see from the responses, many Americans aren't anxious to add a third-world economy to our nation. Apparently, though, we taxpayers (you know, those who are paying the bills down in PR) don't get any say in this process in your scenario.