In the 1984 elections, which put an end to de facto rule, he was selected as vice-presidential running mate of Alberto Zumaran, the candidate of the majority faction of his party, Por la Patria.
The leader of the Por la Patria faction, Wilson Ferreira Aldunate, was imprisoned and prohibited from running for president.
After taking office as Vice President of Uruguay in March 1990, Aguirre supported with a varying degree of enthusiasm the free-market policies espoused by the Lacalle administration.
In March 1993, Renovación y Victoria abandoned the coalition government of Lacalle, although Aguirre remained as vice-president (the vice president in Uruguay is elected by the people for a fixed five-year term).
In recent years, Aguirre abandoned active politics, his faction, Renovación y Victoria, effectively disappearing after 1999.