Colombians vote for a president on Sunday in the tightest election in two decades that may determine whether the country continues peace talks with leftist guerrillas or steps up its battlefield offensive to end a 50-year war, Reuters reported. The vote has largely become a plebiscite on President Juan Manuel Santos' strategy of negotiating disarmament of Marxist FARC rebels to end bloodshed that has killed some 200,000. Santos and Right-winger Oscar Ivan Zuluaga are polling neck-and-neck following a race marred by accusations of electronic espionage and drug-linked campaign financing. Neither is seen winning enough votes to avoid a June 15 run-off.