He led the Navy–Culebra protests that succeeded in the United States Navy abandoning the use of the Puerto Rican island of Culebra for military exercises and was a leader for the Cause of Vieques.
Although he has had limited success at the voting booth regarding his candidacy for the post of Governor of Puerto Rico in 1976, 1980, 1988, 2000 and 2004 — losing every time to either the Popular Democratic Party (PPD) or the New Progressive Party (PNP) candidate — he, nevertheless, has enjoyed great electoral success regarding his candidacy to the Senate, receiving more votes than any other candidate in the Puerto Rican senatorial elections of 1972, 1984, 1992 and 1996.
He was also re-elected to at-large senatorial seats at the Puerto Rican Legislative Assembly on three additional occasions: 1984, 1992, and 1996.
[citation needed] Berríos believes that there should be a change in the U.S. maritime laws that force Puerto Rico to import and export goods only via U.S. ships.
[5] In 1971, Berríos led the Navy-Culebra protests that criticized the United States Navy's use of the Puerto Rican island of Culebra for military exercises.
[6] On May 8, 1999, Berríos began camping inside the U.S. Navy bombing practice grounds in the island of Vieques, Puerto Rico (see Navy-Vieques protests).
"[9] With the continuation of bombing practices by the U.S. Navy, Berríos announced his intention to enter the restricted grounds for a third time.
He stayed for five days in the target practice area, before being arrested violently and forced to lie on a hot gravel road for an extended period of time after being handcuffed with his hands to his back with the other PIP members that accompanied him at the U.S. Navy bombing range.