Zacaria Candao became the second governor of the Maguindanao province succeeding Simeon A. Datumanong. He resigned on April 1, 1977. Sultan Kudarat Municipal Mayor Sanggacala M. Baraguir was appointed by then President Ferdinand Marcos to succeed Candao.[3]
During the 1986 Philippine presidential snap election, Candao supported the candidacy of Corazon Aquino as provincial chairman of the Maguindanao del Norte and Cotabato City chapter of the United Nationalist Democratic Organization, an opposition party which is against the administration of then-incumbent President Ferdinand Marcos. He linked the interests of Muslim Filipinos in the UNIDO platform and facilitated the defection of Filipino Muslim politicians who were part of Kilusang Bagong Lipunan, the ruling party, to UNIDO.[4] Marcos contested win over the 1986 elections later led to his ouster in the People Power Revolution of February 1986 which saw Corazon Aquino installed as President of the Philippines.
After the People Power Revolution, Candao was appointed as acting governor of Maguindanao on April 5, 1986 by then President Corazon Aquino.[3] He was also the acting chairman of the Executive Council of the Regional Autonomous Government for Central Mindanao.[5] Candao was elected as Maguindanao's governor in 1989, he later resigned to run as governor of the then-newly created Autonomous Region in Muslim Mindanao and was succeeded by Vice Governor Norodin Matalam as Maguindanao governor.[3]
Candao participated in ARMM's first gubernatorial elections on February 12, 1990[6] and was elected as the autonomous region's first governor. He officially assumed the post months later on July 6, 1990.[2] He vied for a second term in the 1993 March elections but lost to Lininding P. Pangandaman.[7]
After being the ARMM regional governor, Candao ran again for the post of Governor of Maguindanao in 1995. He was successful and won re-election in 1998. He lost to Andal Ampatuan Sr. in the 2001 elections.[3]