Ljubetic graduated from Colegio Seminario Pontificio Menor and later attended the Faculty of Law at the University of Chile.

In 1984, he became the president of the university's student federation, leading protests against the military dictatorship of General Augusto Pinochet.

[4] As a member of the Christian Democratic Party (PDC), Ljubetic coordinated the Youth Movement for the "No" campaign in the 1988 plebiscite.

[9][10][11] Ljubetic then became the director of the ProyectAmérica Corporation and, at the request of Bachelet, became a member of the Commission for Social Equity.

Ljubetic resigned from the Christian Democratic Party in November 2013 to support the candidacy of former student leader Francisco Figueroa, from the Autonomous Left,[13] for deputy of the Ñuñoa-Providencia district.