WASHINGTON—The rise of dark horse Antanas Mockus to front-runner in Colombia’s presidential race has international tongues wagging. Some see him as a Trojan horse for Venezuela’s Hugo Chavez. Others compare him to Peru’s Alberto Fujimori, who went from outsider to dictator. And then there are those who think Colombians have gone cuckoo after so many years of internal war.

You would be forgiven for shuddering at the thought of a president who, as rector of a university, mooned his students; got married atop an elephant; and, as mayor of Bogota, walked around the capital city in a spandex suit and sent 400 mimes to enforce traffic laws. Not the kind of chap with whom Queen Elizabeth II is clamoring to have tea and scones.

And you would be forgiven for fearing Mockus’ foreign policy after he said he “admired” Chavez for submitting his rule to the ballot box (later downgrading the term to “respect”), or that he would extradite current Colombian President Alvaro Uribe should Ecuador, a Venezuelan ally, seek to try him for Colombia’s incursion into Ecuadorean territory during an attack on a terrorist camp. (Mockus later apologized for not being an international law expert.)

No, Colombians have not suddenly decided to throw away the progress Uribe achieved in cornering the Revolutionary Armed Forces of Colombia (FARC), liberating the economy from insecurity and restoring morale. I would suggest they are trying, awkwardly, to preserve what is best about Uribe while rectifying the excesses of his era.

That Colombians want to preserve what is best is obvious. Juan Manuel Santos, who was Uribe’s successful defense minister, is locked in a close race with Mockus in the first round of the May 30 elections. Mockus has pledged to honor Uribe’s anti-FARC policy and recalled that he was commended by the president when, as mayor of Bogota, he collaborated with his security policy. And Colombia’s leftist party, the Democratic Pole, commands a humiliating 6 percent in the polls.

But Colombians also want to evolve from a country in which a president towered above the institutions to one in which institutions temper political power. Chavez and Fujimori were originally elected by voters sick of weak governments. Mockus, who has risen under a very strong president, says that Colombia’s chief problem is “illegality and the justification of illegality by people who normally behave themselves.” His ethical inclination—substantiated by two corruption-free stints as mayor—resonates in a country plagued with scandals ranging from links between the politicians and paramilitary organizations to political espionage by the secret police.

Mockus’ support comes from young people, urban areas and the middle classes. It is not poor Colombians but the elites who are craving for an end to political excess. The poor are supporting Santos—Uribe’s man. This tension between liberalism (in the classical sense) and authoritarianism has defined Colombian history since the tempestuous relationship between Francisco Santander (vice president) and Simon Bolivar (president) in the republic’s beginning. Presently, the tension occurs not just among Colombians but within Colombians: The same voters who give Uribe a 72 percent approval rating are making Mockus the front-runner.

But a Mockus victory is not a foregone conclusion. His rise as a candidate has been slowed because of his silly statements. Questions abound over his ability to govern considering his party only has five senators and three representatives in the Colombian Congress, and his personal ambitions. Marcela Prieto, executive director of Colombia’s Institute of Political Science, told me that “governability would not be a huge problem because the Liberal Party would back him, although he would have trouble putting together stable coalitions. As regards his unpredictability, the danger is attenuated by the fact that his is not a one-man effort: His campaign has brought together three former mayors of Bogota and the former mayor of Medellin, all of whom have strong egos and will act as checks and balances.”

I have seen too many anti-politicians not to fear Mockus turning into a Fujimori or a Chavez. But the more I observe Colombia, the more I am convinced Mockus’ support is for the right reasons, whether he delivers or not—meaning that Colombians will hold him in check if he wins and becomes messianic, and that they will force Santos to restore the pre-eminence of institutions if he bests his rival. A comforting thought because I too was starting to think that this most admirable of countries was going cuckoo.