government used similar tactics in 1959 after the nationalization of the rail industry, firing thousands of strikers and sentencing union leaders to more than ten years in prison. The CTM approved these and other measures to isolate or eliminate independent unions and rebel movements within its membership. The CTM did not hold a monopoly on labor organizing or even the exclusive relationship with the PRI: the CROM and other organizations also had a formal relationship with the PRI through the Congreso de Trabajo (CT). The CTM had, however, the advantage of State sponsorship, which it used to oppose any independent unions and to hold down the demands of its constituent unions at the behest of PRI leadership. The CTM adopted a practice of entering into "protection contracts"—also known as sweetheart deals—where the workers not only had no role in negotiating, but in some cases did not even know such deals existed. Many of these "unions" degenerated into organizations that "sold" contracts to a CTM affiliate as a guarantee against representation by independent unions, but which did not function as unions in any meaningful sense. The "age of dinosaurs" Those PRI leaders who stayed within the circle of power acquired the derogative nickname of "dinosaurs". Fidel Velázquez was the longest-lived of them all and one of the most conservative as well. Velázquez and the CTM opposed every major movement that ran against the status quo prevalent in the country: in 1968 he verbally attacked the student demonstrators who supported Cuba and demanded democratic reforms in Mexico, calling them radicals inspired by foreign doctrines. The government went further, killing three hundred students in the Tlatelolco massacre that same year. Velázquez openly supported the suppression of this movement. In 1972 the CTM expelled the Sindicato de Trabajadores Electricistas de la República Mexicana (STERM), a union of electrical workers that had demanded union democracy and taken a more militant stance toward employers. When the union did not collapse after pressure from the CTM, the government merged it with another union to form the new Sindicato Único de Trabajadores Electricistas de la República Mexicana (SUTERM). Velázquez intervened in SUTERM's internal affairs to drive out the former leaders of STERM, after which employers blacklisted them and their supporters. Even then, those workers persisted by organizing rallies of more than 100,000 electrical workers and their supporters and calling a strike against the Federal Electrical Commission (CFE) on