Choi was elected to the Irvine Unified School District School Board in 1998 and reelected in 2002. He was elected to the Irvine City Council in 2004, becoming the first Asian American elected to a four-year term on the council. He and Sukhee Kang became the first two Asian Americans and Koreans elected to the Irvine City Council. Choi served on the Irvine City Council until 2012, when he defeated councilman Larry Agran in the mayoral election and was elected to a two-year term as Irvine's mayor. He was later reelected as mayor in 2014. The Irvine City Council is composed of 5 people, including the mayor. The council has 4 Republican members and 1 Democratic member. Choi is a part of the conservative council majority, and has been able to promote programs he supports and stop policies he opposes from being enacted. During the course of new sister city negotiations, he successfully opposed the One-China principle demanded by Shanghai's Xuhui government in the People's Republic of China, which would have required Irvine to abandon its existing long-term sister city relationship with Taoyuan, Taiwan. Choi serves as Chairman of the Orange CountyPublic Library Advisory Board, which consists of Mayors and Council members from 27 Orange County cities, and is also Chairman of the Irvine Library Advisory Committee. He serves on the Orange County Great Park Corporation Board, the Irvine Redevelopment Agency, the Orange County Sanitation District Board and other countywide committees. His vision is to build a large Orange County/City Metropolitan Library at the Great Park. In addition, Choi is a member of the Concordia University President's Advisory Council and is Irvine’s representative to Growth Management Areas 4 and 9 and the Newport Bay Watershed Executive Committee. He formerly represented the 71st Assembly District on the Orange County Republican Party Central Committee. On June 3, 2008, he became the only incumbent to not be re-elected to the Orange County Republican Party Central Committee, coming in seventh with only 6.5% of the available vote. He is also a member of the Local Elected Officials Association and the 400 Club. In 2010, Choi sought election to the California State Assembly, but narrowly lost the Republican primary to Donald P. Wagner, who went on to win the general election. In 2016, Choi won election to the California State Assembly, narrowly defeating AnaheimCity CouncilmanHarry Sidhu in the primary and winning the general election with 60% of the vote.
2016 California State Assembly
2018 California State Assembly
2020 California State Assembly
Family
With his wife, Janie, and their two children, Choi has lived in Irvine since 1993 and in Mission Viejo from 1981–1993. Both of their children attended public schools in the Irvine Unified School District. His son Daniel, is a physician at Kaiser Permanente in Orange County. His daughter Michelle, is an attorney working in Irvine.