Chou began his political career as party spokesman, for the Kuomintang as a whole and specifically for the party's Culture and Communications Affairs Committee, later rising to assistant director of the committee. Chou then represented
Lien Chan and
James Soong, who fielded a joint ticket in the 2004 presidential elections. Chou was first elected to the
Legislative Yuan in that year's legislative elections, despite the loss of the
Pan-Blue coalition's presidential ticket. During his first legislative term, Chou supported stringent monitoring of Taiwan's foreign aid budget as a buffer against
checkbook diplomacy. He also brought attention to weakening infrastructure and multiple nationwide violations of the School Health Act, calling out educational institutions that did not employ the number of nutritionists the law required. Chou led allegations of forgery against
National Taiwan Normal University president Huang Kuan-tsae in 2005. In 2006, the Kuomintang Youth Corps was established. Chou contested the organization's top leadership position, and lost to
Lin Yi-shih. Later that year Chou voiced public support for Taipei mayor
Ma Ying-jeou, who was under investigation for corruption. In August 2007, Ma was found not guilty. Chou won reelection to the legislature in 2008 while serving as Ma's presidential campaign manager. In his second term, Chou was rated highly by the Citizen Congress Watch. Legislative positions he held during this time included deputy secretary general of the KMT caucus. Chou also led the Foreign and National Defense Committee with
Chang Hsien-yao. Chou visited Nicaragua in May 2009, as part of a government delegation led by Ma. Chou backed Chang in his bid for the Kaohsiung mayoralty in 2010. Later that year, the
murder of Weng Chi-nan was solved when the suspect sought Chou out and asked him to arrange terms of surrender. Chou faced
Chen Yu-mei in a party primary during his second reelection bid until she dropped out April 2011. Chou subsequently lost the 2012 election to
Pasuya Yao. As a legislator, Chou was involved in issues pertaining to education, the
foreign relations of Taiwan, immigration, and public safety. He has repeatedly criticized China for its suppression of Taiwan on the international stage. ==Career in entertainment==