Political career
Manzano entered politics in 1998 when he ran for Vice Mayor of Makati as a Liberal. He garnered a majority of votes in the election, but his proclamation was suspended due to a case filed which alleged that he was not a Filipino citizen because he was born in the United States. The Supreme Court (Mercado v. Manzano) eventually ruled that he was indeed a Filipino citizen, clearing the way for his proclamation as Vice-Mayor. Following a three-year term, he lost his bid for campaign for Mayor of Makati in 2001 to Jejomar Binay.
In February 2004, Manzano became the first chairman of the Optical Media Board (OMB), a government agency tasked with combating optical media piracy. He resigned from the position in August 2009.
Manzano ran as the Lakas–Kampi's candidate for Vice-president in the May 2010 election as the running mate of presidential candidate Gilbert Teodoro. He lost again to Makati Mayor Jejomar Binay, placing fifth.
In 2016, Manzano ran for a seat in the Senate, as part of the Partido Galing at Puso coalition of presidential candidate Senator Grace Poe. He lost, finishing 21st overall.
In 2019, Manzano ran for Representative of San Juan under the Pwersa ng Masang Pilipino. However, he was disqualified by the COMELEC due to concerns regarding his citizenship.
In 2022, Manzano supported Leni Robredo's campaign and some of its senatorial slate members, but blasted his former rival Jejomar Binay, who was also a member of the slate, and supported his friend and former running-mate Gilbert Teodoro's senatorial campaign.
