He graduated from University High School (UHS) in Río Piedras, Puerto Rico, in 1974, where he served as student council president, studied from 1974 to 1977 at the UPRRP College of Business Administration, and in 1980 obtained his Juris Doctorate from Tulane University Law School. While in college, McClintock, along with Puerto Rico's former governor Luis Fortuño, founded the Puerto Rico Statehood Students Association, a student organization that promoted absentee voting in favor of the reelection of Governor Carlos Romero Barceló in 1980. McClintock never applied for admission to the bar, neither in Louisiana nor in Puerto Rico, as his intention was not to practice law but to be a public servant. He began that public service before law school, as the 19-year old staff director for the Puerto Rico House of Representatives Consumer Affairs Committee. He subsequently served as a legislative assistant to the New Party for Progress House delegation.