Colombia resumed its path toward peace with leftist rebels Monday, bolstered by President Juan Manuel Santos’ victory in elections seen as a referendum on his bid to end the 50-year-old conflict. Santos picked up 50.95 percent in Sunday’s runoff against the more conservative Oscar Ivan Zuluaga, validating his insistence on continued negotiations with the Revolutionary Armed Forces of Colombia and the smaller National Liberation Army. Santos, a center-right politician who received the backing of some leftist parties, had staked his presidency on a negotiated peace with the FARC. Founded in the 1960s, the ELN and the FARC have been perennial protagonists in Latin America’s longest guerrilla war.