Puerto Rican citizenship
In 1952, upon U.S. Congress approving the Constitution of the Commonwealth of Puerto Rico, also reaffirmed that Puerto Rican citizenship continued in full force. This was further reaffirmed in 2006 while the U.S. Senate probed into the President's Task Force on Puerto Rico's status. In 1953, U.S Ambassador Henry Cabot Lodge Jr., in a memorandum sent to the United Nations, recognized that "the people of Puerto Rico continue to be citizens of the United States as well as of Puerto Rico."
Implications of Puerto Rico's current political status
Since Puerto Rico is an unincorporated territory (see above) and not a U.S. state, the United States Constitution does not fully enfranchise US citizens residing in Puerto Rico.