MEXICO CITY—Were Enrique Pena Nieto eligible for re-election in Mexico’s 2018 presidential race, most analysts believe he would be soundly beaten. Pena Nieto is plagued by corruption scandals, rising crime rates and, above all, the sense that he represents the very worst of the country’s oldest political party, the Institutional Revolutionary Party, or PRI; his six-year-term, which ends next December, has exposed many of the fault lines that continue to undermine Mexico’s potential. Add U.S. President Donald Trump’s bullying tactics on trade and border security, and the resurgence of veteran leftist Andres Manuel Lopez Obrador in the polls, and until […]