By Helen Murphy BOGOTA (Reuters) – President Juan Manuel Santos vowed to bring peace to Colombia after winning re-election on Sunday, telling Marxist rebels his victory shows that voters demand an end to five decades of war. Santos, a center-rightist who has staked his reputation on securing a peace deal with the Revolutionary Armed Forces of Colombia (FARC), won almost 51 percent support in the runoff election on Sunday. His right-wing rival Oscar Ivan Zuluaga trailed with 45 percent. The election divided Colombia between voters who support a deal to end Latin America’s longest-running insurgency and Zuluaga’s backers who want to force the rebels into a battlefield surrender.