In 1974, he was expelled from university again due to his involvement in the National Democratic Youth and Students Union case.

In 1990, Kim Moon-Soo participated in the foundation of the Popular Party, and served as chair of the Labor Relations Committee.

(Sosa-gu, Bucheon) Following his election, Kim Moon-Soo served as a member of the legislature, focusing on labor and environmental issues, as well as on transportation in the Seoul metropolitan area and childcare.

In April 2012, Kim Moon-Soo declared his presidential candidacy in the primary election of the Saenuri Party.

[1] In announcing his candidacy, Kim asserted that the nomination of Park Geun-hye should not be viewed as axiomatic, despite a decade of preparation for the campaign on her part.