In 1948, Calderón ran for president again. Otilio Ulate Blanco defeated him by 10,000 votes in a very questionable election (since Calderon's party actually received more votes for Congress than Ulate's party at a time when the Costa Rican society was heavily polarized, suggesting the non-likelihood of a "split vote"). Ulate was proclaimed winner by the two of three members of the Electoral Board. However, the Congress, controlled by Calderón's party, declared the election to be null and void and that a new election would be held.
