WASHINGTON — The Supreme Court has upheld the differential treatment of residents of Puerto Rico, ruling that Congress was within its power to exclude them from a benefits program that’s available in all 50 states and the District of Columbia.The court held by an 8-1 vote Thursday that making Puerto Ricans ineligible for the Supplemental Security Income program, which provides benefits to older, disabled and blind Americans, did not unconstitutionally discriminate against them.Justice Sonia Sotomayor, whose …