[5] After his career in public service, Descartes served as president of the Interamerican University of Puerto Rico from 1970 to 1977.
After supporting the status quo as a member of Puerto Rico's Popular Democratic Party for many decades, he was appointed by Governor Luis A. Ferré as a member of the Ad Hoc Committee that studied the extension of the presidential vote to Puerto Rico.
In the 1970s his sympathies for statehood became apparent, as Jose Trias Monge noted in his book "Historia Constitucional de Puerto Rico, Vol.
V" and he became active in the Puerto Rico Statehood Commission headed by then Rep. José Granados between 1981 and 1986.
[6] His archives were donated to the Center for Historical Research or Centro de Investigaciones Históricas (CIH) of the University of Puerto Rico at Río Piedras.