The SNTE grew to be the largest single labor union in Latin America, and its head, Elba Esther Gordillo considered the most powerful woman in Mexican politics. The lack of democracy within the teachers' union has been as a source of conflict. Also a source of conflict is union opposition to reforms that undercut union power over teaching positions. In 2012, some teachers from rural areas, specifically, from Michoacan and Guerrero states, opposed federal regulations that prevented them from automatic lifetime tenure, the ability to sell or will their jobs, and the teaching of either English or computer skills. The head of the SNTE since 1989 was arrested in 2013 as she got off her private airplane in the Toluca airport, and charged with corruption.