Well it depends if PR's political landscape remains divided along the lines of the PPD, PIP and the PNP, or quickly reorganizes itself along Democratic and Republican lines. The former would be interesting from a political perspective- a rather Canadian-style arrangement, actually.
Highly unlikely, though. The main issue dividing the PNP Democrats from the PPD Democrats is statehood. Once statehood is done, it's hard to see why both sides wouldn't join the Democratic Party, and then the PNP Republicans are left to join the Republicans or waste away into irrelevance (which they would regardless, but still). The PIP might stick around and get as much as 10% of the vote, but they're an irrelevant nuisance right now, and it's hard to see them getting many heavyweights from the PPD to defect to them and not the Democrats.
