[6] In this position, he acted as spokesman for the party in the 2004 legislative elections,[7] and offered to resign after the Pan-Green Coalition failed to win a majority.

[8] He joined the People Sovereignty Action Network and protested the 2010 signing of the Economic Cooperation Framework Agreement.

[10][11] Chung acted as Pingtung County Government spokesman during the 2014 Taiwan food scandal, accusing the Ministry of Health and Welfare of "setting up" Pingtung in a leak of confidential information to Ting Hsin International Group, one of the companies involved in the food scare.

[14] In May 2016, Chung became one of the first ten legislators to support an amendment to the Act of Gender Equality in Employment intended to lengthen the period of maternity leave given to partners of unmarried women.

[15] Later that month, he was named the founding chairman of two legislative groups intended to further Taiwan's relations with European nations.

[16] In May 2017, Chung founded the "Renewable Power Promotion Alliance" alongside fellow legislators Chen Man-li, Su Chih-fen, and Yang Yao.