From 2012 to 2015 he was a local deputy of the LXV legislature of the Congress of Chiapas for the Institutional Revolutionary Party (PRI) representing district 1, based in Tuxtla Gutiérrez, serving as president of the board of directors.[4] From 2014 to 2017 he was president of the municipal steering committee of the PRI in Tuxtla Gutiérrez.[2]
In the 2018 federal elections, Noé Castañón stood as a substitute for Eduardo Lozano Grajales for the position of senator of the republic representing the state of Chiapas for the Todos por México coalition, made up of the Institutional Revolutionary Party (PRI), the Ecologist Green Party of Mexico (PVEM) and New Alliance (PANAL). On June 1, a month before the elections, Lozano Grajales submitted his resignation to his nomination for the Senate, asking that his place be filled by Alejandra Lagunes. However, the National Electoral Institute (INE) determined that the application could not be delivered to another person. Consequently, Noé Castañón remained as the only member of the formula. In the July 1 elections, the candidacy presented by the "Todos por México" coalition won the first minority seat in Chiapas, a position that Castañón would occupy as a substitute for Lozano Grajales. On July 3, Eduardo Lozano Grajales asked the electoral authority to annul his resignation in order to occupy the seat he had abandoned before the elections; however, on July 7, the INE ratified Lozano Grajales' resignation and the obligation that the seat was occupied by Noé Castañón.[5]
