At Military Camp No. 1, the big modern army base outside Mexico City, steel gates clanged shut on more than 1,000 railroad workers one night last week. Troops guarded stations, and the government-owned railways sent out a call for strikebreakers to man the trains. After two tries at dealing with Demetrio Vallejo, 45, the brash, baby-faced new leader of the Railway Workers Union, President Adolfo López Mateos set out to crush him.
Vallejo's first strike, which he led as a rank-and-file rebel with no union post, forced the government to agree to union elections that swept Vallejo into office (TIME, Aug....