I've learned that if the US Congress really decides they want to admit PR, there's really nothing the new governor can do about it.
Ordinarily, a territory has to call a constitutional convention, set up a republican form of government, and the people have to vote on an up or down vote on the proposed constitution and government.
Puerto Rico has a constitution and a republican form of government. There is nothing for PR's governor to veto. Congress could just proceed straight to a vote.
<ptp> how many emo kids does it take to change a lightbulb?
<Willy> HOW MANY?!
<ptp> none they just sit in the dark and cry