1. López Obrador, rightly or wrongly, has lost twice. Whether he would have squeaked by in fairer elections, it appears that the Mexican left is not a majority phenomenon. From the Zapatistas to the Oaxaca worker organization APPO, the left in the country seems to be regionally differentiated. Nevertheless, I agree with Shane that this is substantially shaped by media ownership. The increased ubiquity of mass media and communications, and the increased international integration of the major corporations, mean that media ownership is becoming more important over time in constraining the class struggle, not less. Would Peña Nieto have won without Televisa?
U.S. Embassy cables from Wikileaks provide support for the supposition that he would not have: <http://cablegatesearch.net/cable.php?id=09MEXICO212#para-12944-7>
2. Nieto is a name of Sephardic Jewish origins. Since the name comes from his maternal side, it's quite possible the new Mexican president is of Sephardic ancestry.