Prior to this, he served as Lieutenant Governor of New Mexico from 1971 to 1975 and from 1979 to 1983, and as a state representative. He currently serves as special water projects coordinator for the New Mexico state engineer"s office and the Interstate Stream Commission. Mondragon later returned to the Democratic Party.
Roberto Mondragon briefly appeared in the 1988 movie The Milagro Beanfield War, set in northern New Mexico, as a townsperson.
Mondragon is a partner in Aspectos Culturales, a non-profit, Santa Fe based firm dedicated to maintaining Hispanic Heritage.