As campaigning closes for Colombia’s May 30 presidential elections, polls placed the two frontrunners neck and neck in what has become a dramatic race between Bogota’s ex-Mayor Antanas Mockus and former Defense Minister Juan Manuel Santos. Green Party candidate Mockus surged on what’s become known as the ola verde—or green wave—to become a top contender. He faces Santos, seen as an heir to the popular president, Álvaro Uribe. After a long wait for an official decision on whether Uribe would be able to pursue a third term, Colombia’s Constitutional Court rejected a reelection referendum in February and the presidential race got off to a gallop. Although several candidates remain in the running, the competition became a two-horse race between Mockus and Santos in recent weeks. Still, Colombians may face another wait come May 30. Polls show neither Mockus nor Santos winning more than 50 percent of the vote, the needed portion to avoid a runoff election. A second round of elections would occur June 20.