Chiang was inspired to enter politics after witnessing the
Sunflower Student Movement in 2014. and resigned from his law practice.
First term , in October 2015On March 29, 2015, Chiang announced his bid to represent
Taipei City Constituency 3 as a member of the Kuomintang. In the party primaries, he ran against KMT legislator
Luo Shu-lei, who previously held the constituency seat, and
Wang Hung-wei, a KMT member of the
Taipei City Council. After Luo failed to build a minimum lead majority of five percent in the April 2015 party primary, Chiang advanced to a second primary. After winning the KMT nomination for Taipei's third constituency, Chiang ran for the seat in the
2016 legislative election. The
Democratic Progressive Party (DPP) originally nominated
Liang Wen-chieh to challenge Chiang in the race, but Liang withdrew; , a psychiatrist and
independent candidate, joined the DPP and received the party's nomination to run against Chiang instead. On election day January 16, 2016, Chiang defeated Pan with a majority of 83,476 votes, compared to Pan's 66,998 share. He announced his victory at 7:40 p.m. that same day. Chiang's successful campaign to represent the third constituency of Taipei in the
9th Legislative Yuan came in contrast to the results of other KMT lawmakers in the 2016 legislative election, which saw the DPP flip traditionally KMT constituencies to win a clear majority. Chiang attributed the Kuomintang's losses in the elections to "ineffective governance". portrait In November 2015, Pan filed a legal motion to invalidate the results of the election, alleging that Chiang used a lottery to bribe voters during his campaign. On March 23, 2016, the Taipei District Prosecutors' Office concluded that there was insufficient evidence of vote buying, and thus would not press charges against Chiang, though Pan also filed a civil lawsuit to invalidate the election results which were heard in court in April 2016. In May 2016, the
Taipei District Court ruled in favor of Chiang and dismissed Pan's lawsuit. The case ended on December 27, 2016, when the Taipei
high court rejected an appeal by Pan to review the dismissal. On February 1, 2016, Chiang was sworn in as a member of the 9th Legislative Yuan. As a legislator, he was a member of the Legislative Yuan's Social Welfare and Environmental Hygiene Committee responsible for proposing motions regarding
elderly care,
child welfare, and
food safety. During his tenure, he became known for his opposition to proposed amendments to the and, during a 2019 protest in the legislature, drew widespread online attention after an image of legislator
Chen Yu-jen embracing him during the protest went
viral on social media.
Second term Chiang ran for re-election in the
2020 Taiwanese legislative election. DPP spokeswoman was initially considered to contest Chiang's seat in the Taipei third constituency, but she declined the party's nomination. On August 27, 2019, the DPP nominated former investment banker
Enoch Wu to challenge Chiang instead. The race drew media attention as a "battle of two handsome men," both of whom came from prominent backgrounds and had a strong presence on social media. Chiang's campaign emphasized his
grassroots initiatives in Taipei, such as the establishment of citywide
legal clinics, while Wu, an advocate of
Taiwan independence, campaigned on pro-democracy issues and
cross-strait sovereignty. On January 11, 2020, Chiang received a majority of 95,559 votes (51.1%)—compared to Wu's 82,453 (45.75%) share—and was re-elected for a second legislative term. His victory in that year's legislative election made him a leading KMT candidate for the Taipei mayoralty. He was sworn into the
10th Legislative Yuan on February 1, 2020. During his second term, Chiang presided over the founding of new legal clinics in
Shilin District and
Beitou District. In January 2021, he proposed a legislative amendment expanding compensation to
White Terror victims. According to the
South China Morning Post, Chiang was "rated as one of the best and most attentive lawmakers by local political monitoring groups" throughout his tenure in the Legislative Yuan. == Mayor of Taipei (2022–) ==