Not unless we get to balance them out by acquiring the Western Canadian provinces. Remember that statehood confers them with 2 U.S. Senators plus some representatives in the House.
That Puerto Rico would be a democrat state is mere speculation. You cannot anticipate actual Puerto Rico's voting trends based on voting trends on some mainland so-called Puerto Rican communities. In fact, it has been reported in more places than one that "Hispanics" carried Bush-Cheney in the last election, particulary in the I-4 corridor of Florida, which counts with a large conservative Puerto Rican population, as opposed to the liberal/democrat "Puerto Rican" communities of the north east.
I'll bet you a case of rum that the actual Puerto Rico, not to be confused with East Harlem, would be a Republican state. Just with its large Catholic or Evangelical Christian population, and its small business/entrepeneur-dominated economy it would be easy for the GOP to secure a strong base here.