Los Angeles (AFP) – President Joe Biden’s plans to reboot US engagement with Latin America — especially over critical topics like migration — took a major hit after key partner Mexico snubbed a regional summit opening Monday in Los Angeles to protest the exclusion of three far-left countries. What was meant to be a week-long showcase of cooperation looks more likely to become a display of division that reflects diminishing clout over a region where long-time US economic and diplomatic influence faces a growing Chinese challenge. Confirming it was not inviting Cuba, Nicaragua and Venezuela to…