Lúder was born in Rafaela, Santa Fe Province. He enrolled at his province's National University of the Littoral, where he received a "juris doctor" in 1938. Lúder was first elected to a seat in the Constitutional Convention of 1948, which drafted president Juan Perón's 1949 replacement of the 1853 Constitution of Argentina. Following Perón's 1955 overthrow, however, the original document was reinstated, and the exiled Perón entrusted Lúder with his legal defense "in absentia" vis-á-vis extensive corruption charges.