Generally, on the pro-statehood side is the New Progressive Party, which identifies with mainland Republicans.
But pro-statehood sentiment is gaining steadily, and independence has only a small minority of advocates.
The majority PPD supported the plebiscite, but it was boycotted by the pro-statehood and independence parties.
"They are real heroes," said Peddi Sudarshan Reddy, a member of the governing council of the main pro-statehood party.
On the island, there is a strong pro-statehood movement struggling to make it the 51st state.
Puerto Rico has its first Republican governor in decades, Luis G. Fortuño, a pro-statehood conservative who has cut the number of public employees by about 17,000.
Now, pro-statehood activists were joining the effort, out of frustration with Washington's apparent reluctance to either embrace statehood or expand Puerto Rico's autonomous powers.
However, no other action was taken, partly because political power on the island began to alternate between pro-commonwealth and pro-statehood parties.
Mr. Pierluisi, who is pro-statehood, correctly called the island's current status "colonial in nature" and made a forceful argument against those who would dismiss the election's outcome.
However, with the charismatic Muñoz Marín retired from the political scene, the PPD lost its firm grip on power and was fiercely opposed by pro-statehood groups.
