A senatorial election was held on November 10, 1959, in the Philippines. The 1959 elections were known as the 1959 Philippine midterm elections as the date when the elected officials take office falls halfway through President Carlos P. Garcia's four-year term.
The Liberal Party continued chipping away from the Nacionalista Party's dominance in the Senate, winning two more seats, although the Nacionalistas still possessed 19 out of 24 seats in the chamber. The Grand Alliance (GA) coalition, formed between the Progressive Party of the Philippines (PPP) and defectors of the Nacionalista and Liberal parties, did not win any Senate seat despite being supported with an influence campaign by the United States' Central Intelligence Agency.
Philippine Senate elections are held via plurality block voting with staggered elections, with the country as an at-large district. The Senate has 24 seats, of which 8 seats are up every 2 years. The eight seats up were last contested in 1953; each voter has eight votes and can vote up to eight names, of which the eight candidates with the most votes winning the election.
No incumbents retired on this election.
The Nacionalista Party won five seats contested in the election, while the Liberal Party won two, and the Nationalist Citizens' Party won one.
Lorenzo Tañada of the Nationalist Citizens' Party and Nacionalistas Mariano Jesús Cuenco, Fernando Lopez, and Eulogio Rodriguez defended their Senate seats. Lopez was originally from the Democratic Party, and ran as a Nacionalista on this election.
The two winning Liberals are neophyte senators: Estanislao Fernandez and Ferdinand Marcos. Also entering the Senate for the first time are Nacionalistas Alejandro Almendras and Genaro Magsaysay.
Incumbent Nacionalista senators Edmundo B. Cea and Emmanuel Pelaez both lost.
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