Puerto Ricans who live in Puerto Rico like many other Latinos that live in Latin America are very conservative when it comes to social issues (anti-abortion, anti-LGBT, anti-gun control, etc). To be fair, many Black people here in America are also socially conservative but due to the Republicans history of overt and covert racism towards Black people, most of those Black voters still vote for the Democratic Party.
Island-living Puerto Ricans don't have the knowledge or history of the Republicans. However, Puerto Ricans that have been living in the mainland US for decades vote overwhelmingly for the Democrats. Additionally, Republicans opposition to PR statehood and Trump's response to Hurricane Maria will make PR a likely blue/Democratic state for the foreseeable future. PR would be more competitive for Republicans on a local level though.