In 1974, Maldonado Venegas joined the Institutional Revolutionary Party and began studying his law degree at the UNAM and Escuela Libre de Derecho.

[2] After two years in the Secretariat of Public Education, Maldonado went to the PRI to serve as the deputy coordinator of planning and organization in its 1994 presidential campaign.

He returned to the government after the election of Ernesto Zedillo and served in the Secretariat of the Interior, as a presidential adviser, and as the technical secretary of the Intersecretarial Commission for the Fostering of Federalism.

[2] After brief stints in the Secretariat of Social Development and as the president of the Board of Directors of the National Arid Zones Commission, Maldonado returned to PRI service in time for the 2000 presidential elections.

[5] On February 1, 2011, Maldonado left the Senate, coinciding with the installation of a new government in the state of Puebla,[6] in which Convergence was part of the winning coalition.

[2] In 2015, Maldonado was placed on the PRD's list of proportional representation federal deputies from the fourth region and won a seat in the LXIII Legislature.