Colombians select their president Sunday in a close runoff contest between the two leading contenders, President Juan Manuel Santos and former Finance Minister Oscar Ivan Zuluaga.

Their choice will set the country's course - either more corrupted politics as usual or a clean break from the past with a candidate bearing a spotless reputation. It also will determine whether the closest U.S. Latin American ally will remain a reliable regional partner.

The differences in the candidates are sharp. Santos boasts the overwhelming support of the country’s media, numerous business magnates and far left political parties, plus a huge campaign fund. Zuluaga is a highly respected former businessman and minister who enjoys the strong support of former President Alvaro Uribe, the country’s most favored political leader.

In the last four years, Santos has moved from being a political disciple of Uribe to launching lengthy ad hominem attacks on the man whom he served as defense minister and who handed him the presidential nomination in 2010. Much of his shift in allegiance has to do with his sharp turn to the left, coupled with a politics that relies on massive monetary gifts to countless politicians throughout government.

Santos’ leftward march has been capped in the last year with alliances that are extraordinarily unpopular. His chief political adviser is disgraced former President Ernesto Samper, who notoriously escaped jail despite having accepted $20 million from the most notorious drug trafficking family in the country.

Moreover, Santos has virtually allied himself with the FARC, the detested, drug-trafficking communist group that has waged a 50-year civil war. The group’s nearly universal lack of popular support notwithstanding, FARC operatives are very effective in intimidating voters and controlling precinct voting results, particularly in the country’s south.

Despite a disapproval rating of 56 percent, Santos finished second with 25.7 percent of the vote in first round elections in May, marginally better than his 25 percent showing in a February presidential poll by Ipsos Napoleon Franco. In contrast, Zuluaga took first place in the first round with 29.3 percent, more than three times better than an 8 percent showing in February’s poll.

In many respects, Zuluaga must be considered the underdog, despite polls taken in the last two weeks that show him leading Santos. Santos has a large organization of well-paid workers, while Zuluaga’s Centro Democratico party is a recent reclamation from obscurity by Uribe. His 62 percent popular support was key to Zuluaga’s besting Santos in May’s first round.

Latest polls by professional firms reflect a tossup. On June 5, Gallup called the race a dead heat with Zuluaga marginally leading at 48.5 and Santos at 47.3. The next day, Cifras y Conceptos reported 43.4 percent of respondents for Santos and 38.5 percent for Zuluaga; while Ipsos Napoleon Franco gave 49 percent to Zuluaga and 41 percent to Santos.

Santos has centered his campaign on his vaunted peace process with the FARC, based on faltering negotiations in Havana. In the process, his negotiating team has reached an agreement for controlling the drug traffic – which most Colombians don't believe will happen – and will accept FARC’s participation in politics.

In a recent presidential debate, Santos accused his opponent of being against peace, to which Zuluaga responded that he supported peace but not at the price of the country’s heritage and allowing FARC to participate in any public activities.

Santos has so far spent more than $3 billion in public funds, spreading what he terms “marmalade” among members of the Congress and Senate, as well as other key political figures. Unfortunately, similar to what has lately been the case in the U.S., there has scarcely been a mention of this unprecedented practice in the press, which not surprisingly has been courted financially by the Santos camp.

Thus, the lines are clearly drawn. Will the highly financed, clearly corrupt Santos organization successfully re-elect their unpopular president, or will Colombia’s voters opt for a refreshing call to clean governance?

"Ian Alexander" is the pen name of a veteran journalist working in Colombia. Thinking of submitting an op-ed to the Washington Examiner? Be sure to read our guidelines on submissions for editorials, available at this link.