I thought there could be 2 hurdles:
* Puerto Rican polls probably have to be Spanish-only
* Usually, when US-based pollsters poll a US state, let's say Michigan, they get telephone numbers from a different company using registered voter rolls. Is that possible for Puerto Rico too ?
In 2008, only Puerto Rico-based pollsters polled the race, but not US-based like PPP, Rasmussen etc.
The first seems unlikely, since polling companies poll in the southwest.
I don't why the second wouldn't be possible. Expense maybe?