Mexican ruling party roiled by chief refusing to step down in leadership tussle

Mexican President Andres Manuel Lopez Obrador's ruling party plunged into a divisive leadership struggle on Monday whenparty chief Yeidckol Polevnsky refused to stand down after being voted out by opponents.Lopez Obrador's National Regeneration Movement (MORENA) party reshaped Mexico's political landscape with a convincing victory in the 2018 elections, winning majorities with its allies in both houses of Congress.Divisions in MORENA at a time when the economy is stagnant and homicides are at re