The two main traditional factions of PUSC (Calderonistas and Liberals) competed for the nomination.

Hernández was nominated by the group “Calderonista Convergence”, close to former president Rafael Ángel Calderón Fournier who personally endorsed Hernández and followed the “Calderonism”[1] (the historical ideology of 40's caudillo and Fournier's father Rafael Ángel Calderón Guardia, a Christian socialist) whilst Piza was endorsed by the Social Christian Rebirth group, part of the more right-wing Liberal faction led by former president (and Fournier's rival) Miguel Ángel Rodríguez Echeverría.

[3] Hernández won the primary by a landslide victory with 77% of the votes and nominates Piza as his Vice-president.

[4] Nevertheless, Hernández would resign his candidacy a few months later accusing the Party's leadership of treacheries and backstabbing.

Piza took over the candidacy reaching only 6% of popular vote on the presidential ballot, but increasing its support for Congress to the point of duplicating its number of deputies.