Prior to winning his first Legislative Yuan term in 2001, Kuo served two terms as mayor of Guanyin, Taoyuan, from 1994 to 2002.[1] He won reelection to the Legislative Yuan in 2004.[2] In November 2003, Kuo Jung-tsung, Kuo Wen-cheng [zh], and Hsieh Ming-yuan fought Chung Shao-ho on the floor of the Legislative Yuan. Chung had pulled down a protest sign held by another Democratic Progressive Party lawmaker, who was opposing the scheduling of a defense committee meeting on the same day as a gathering of the general legislature.[3] During his first legislative term, Kuo Jung-tsung also commented on the potential pardoning of expelled DPP members,[4] and the possibility of leaking classified military information in a small-scale exercise observed by president Chen Shui-bian.[5] In his second term, Kuo expressed opposition to the legalization of gambling and to investment in China by the Taiwanese technology industry.[6][7]
Kuo lost reelection in 2008 to Kuomintang legislative candidate Liao Cheng-ching [zh].[8] Kuo ran in the by-election for Taoyuan County's 2nd district scheduled after Liao's conviction on vote-buying charges,[9] and defeated Chen Li-ling [zh].[10][11] Kuo was sworn into office on 18 January 2010, and stepped down at the end of his term on 31 January 2012.[12] During the 2010 New Taipei City mayoral election, a document signed by Kuo and Huang Jen-shu [zh] became a topic of discussion. The document claimed that, Eric Chu, during his tenure as Taoyuan County Magistrate, had ended the county government's subsidies for agriculture and the elderly.[13][14] In August 2010, Kuo opposed the nomination of Su Yeong-chin to the post of vice president of the Judicial Yuan, believing that judicial independence would be reduced, as both Su Yeong-chin and his brother Su Chi were close to Ma Ying-jeou.[15] In March 2011, Kuo and fellow legislator Lo Shu-lei [zh] opined that Chunghwa Telecom did not need to charge fees for long-distance phone service, due to the small geographic size of Taiwan.[16] That same month, Kuo also asked premier Wu Den-yih about his position on nuclear power.[17] An analysis by Citizen’s Congress Watch undertaken after the Eighth Legislative Yuan had ended revealed that Kuo had never spoken in any legislative committee for which he held membership.[18]
In 2013, Kuo supported Annette Lu's call to impeach Ma Ying-jeou.[19] The following year, Kuo visited Su Tseng-chang after Su announced that he would not run for reelection as Democratic Progressive Party chair or as the party's Taoyuan mayoral candidate.[20] In November 2014, Kuo ran in the local elections. He was elected to the Taoyuan City Council alongside his niece and former Legislative Yuan aide, Kuo Li-hua.[21][22] Kuo Jung-tsung resigned the council seat in August 2015, before an appeal to the Taiwan High Court regarding violations of electoral law was heard.[23] The DPP chose to back the candidacy of Kuo's son Kuo Yu-hsin over his wife, Kuo Tsai Mei-ying, a former member of the Taoyuan County Council.[21][23] Kuo Yu-hsin lost the by-election to independent candidate Wu Tsung-hsien [zh].[23][24]
