Entering the labor force in 1945 as a peon in his neighborhood's CAMEA steel mill, Miguel took up amateur boxing as a pastime, winning 13 of the 19 matches he fought in; a knockout defeat at Buenos Aires' famed Luna Park led him to abandon the pursuit, however.

This was opposed by Vandor, however, who began calling for a "Peronism without Perón" until a 1966 coup d'état that installed the anti-labor President Juan Carlos Onganía forced organized labor to rally around their exiled benefactor.

The November 1974 election of leftist shop steward Alberto Piccinini at ACINDAR's important Villa Constitución steel mill prompted Miguel to help the company lobby President Isabel Perón (the leader's widow) for an armed intervention, which took place in a March 1975 police assault on the facility.

Rodrigo quickly unveiled an austerity package which, attempting to deal with the country's yawning trade gap, shocked markets with a sudden halving of the peso's value, which paralyzed new construction and industrial spending and threw the CGT (particularly steelworkers) against the plan.

[3] Miguel counted on his former alliance with Acindar CEO José Alfredo Martínez de Hoz (appointed Minister of the Economy by the new regime) and on his friendship with Admiral Massera who, as Head of the Navy became the second-highest ranking public official in Argentina.

Miguel, who led a decimated UOM with a membership (150,000) less than half of its 1970s level, became increasingly marginal to the national discourse; by 1990, he was relegated to helping mediate conflicts between Ubaldini and Alfonsín's successor, President Carlos Menem.

Menem, a lifelong Peronist who had been nominated partly with Miguel's last-minute support, quickly took to privatizing Argentina's array of State enterprises, a surprise move opposed by the CGT for the many layoffs it caused.

[1] Suffering from a worsening kidney ailment, Miguel considered giving his support to San Luis Governor Adolfo Rodríguez Saá's (unsuccessful) candidacy for president; but he died in a Buenos Aires clinic at the end of 2002.