How did class play a role in the developing unrest in Mexico?

Mexico's distribution of income as measured by Gini's Coefficient, has remained unchanged for the last 150 years. Since the 1980s, business leaders were aware that a turn to leftist ideologies would appear after the turn of the century (third millenium), as it actually did. Neoliberalism has been the main ideology since the early 1990s, widening the gap between the affluent and non-affluent. Now Mexico has elected a leftist President, starting December 1st 2018.