Salom studied at the Buenaventura Corrales School from 1958 to 1964 and later at Saint Francis High School from 1965 to 1969. He graduated with a Bachelor's in political science and a doctorate in Government and Public Policy from the University of Costa Rica.
Salom's political career began in his teenage years when he was elected President of the Student Council in 1969. At UCR, he was elected President of the Federation of Students from 1974 to 1975. During this time, he led several student protests. A leftist, Salom was a founder of the Costa Rican Socialist Party and the People's United Coalition. He was elected governor of San José from 1978 to 1982 as a member of People's United.
In 1987, he became an adviser to Javier Solís of the Social Christian Unity Party. Later, with Isaac Felipe Azofeifa and other left-leaning politicians, Salom helped found the Democratic Force party, which held three deputy seats in the 1990s. In 2002, Salom became one of the founding members of PAC.
Salom began leading a group of informal PAC meetings, called the "ungroup."[2] Salom, along with María Eugenia Venegas and Ottón Solís encouraged Luis Guillermo Solís to run for President, which he did in 2014.
