In 1940, he ran as candidate of the Unification for Resident Commissioner and in 1941 was chosen vice-president of that political collectivity. When this party was dissolved in 1944, he began to organize the Progressive Republican Union Party, which in 1948 became the Puerto Rican Statehood Party and in 1953 the Republican Statehood Party. In 1952, he was chosen president of the party and elected in that year's election as Senator at large, position from which he resigned. He was re-elected for the same position in the elections of 1956, 1960, and 1964.