Colombia, one of Washington’s steadiest Latin American allies over many years, might be about to take a big political turn. On Sunday, Colombians head to the polls for the second and decisive round of voting for president. On the hard left is the former guerrilla fighter Gustavo Petro. And on the far right, real estate tycoon and former mayor, Rodolfo Hernandez. Both candidates are political outsiders. But the similarities end there, as Jorge Valencia reports from Vélez, Colombia.