ANTANAS MOCKUS (his full name is Aurelijus Rutenis Antanas Mockus Šivickas) 

BUCARAMANGA, COLOMBIA -- Colombians have long known Antanas Mockus for his antics, such as the time he mooned an auditorium full of rowdy students during his stint as a university president. And how he got married atop an elephant.

Then there were the occasions during his two terms as Bogota mayor when he donned a spandex suit and became Super Citizen to lecture residents about civics.

Some have called him "a little strange," as Mockus acknowledged Thursday in an interview. Soon, Colombians may be calling him president.

Polls increasingly show that Mockus, who is the son of Lithuanian immigrants and whose trademark is an Amish-style beard, might just win the presidency in elections to succeed Alvaro Uribe, a U.S.-backed hard-liner who was prevented from running for a third term. A first round of voting takes place May 30, with a second scheduled next month if no candidate wins 50 percent.

Political analysts and commentators call Mockus's rise a political phenomenon because he differs so markedly in style and substance from Uribe, who marshaled more than $6 billion in U.S. aid to batter the rebel forces that have plagued Colombia. That gave Uribe a 70 percent approval rating, and pundits predicted that his natural heir, former defense minister Juan Manuel Santos, would easily sweep to victory.

Mockus, a 58-year-old former mathematician, likes to say that he is not anti-Uribe but post-Uribe. He has said he would continue popular policies, such as the fight against armed groups, but also pledges to bring civility and transparency to government.

"People are thinking to themselves, 'I am good, and I see myself in this leader, who even appears naively good,' " said Mockus, speaking in a bulletproof 4x4 transporting him to a campaign stop in this northern city. "It is like the people feel the need to believe in a process that calls for people to be good."

Mockus's running mate is a former mayor of Medellin, Sergio Fajardo, also a former mathematician. Two other former Bogota mayors, Luis Eduardo Garzon and Enrique Pe?alosa, campaign alongside them, hammering home the message that they offer technocratic competence and honesty.

'New politics'

Mockus's campaign managers say his administration would contrast sharply with what critics call the downside of Uribe's government: confrontation and scandal, including revelations that the secret police spied on opponents and helped hit men kill leftist activists.

Mockus, who heads the Green Party, has run a shoestring campaign, relying on students adept at getting the word out through Facebook and Twitter.

"People in Colombia are tired of corruption, old-style politics, and Mockus and Fajardo are now trying to represent this new politics," Andres Pastrana, a former president, said in a recent interview.

That Aurelijus Rutenis Antanas Mockus Sivickas would have much of a chance in this country of 45 million would seem surprising, at least on the surface. In some ways, Colombia is an insular, inward-looking country that does not have the immigrant tradition common in other Latin American countries. Colombians rarely elect populists for high office, let alone charismatic, anti-establishment types who are eccentric or prone to sometimes bizarre behavior.

Analysts say that despite his outsider status, Mockus is a savvy political operator. But he is also the natural anti-politician: He gives long, pedagogic answers, laced with references to Kant and Kierkegaard.

He is not afraid to cry in public or acknowledge mistakes. He has also disclosed that he has Parkinson's disease, though doctors say it is not debilitating.

As mayor, he once took a shower on television to push water conservation. He also used mimes to teach Bogota's notoriously discourteous drivers to obey traffic laws.

To his detractors, everything associated with Mockus smacks of naivete and optimism, like the sunflowers that are the symbol of his campaign. Those critics say that Colombia still faces serious threats from the Revolutionary Armed Forces of Colombia (FARC), its largest rebel group.

"The FARC are waiting for Aug. 7 to have a big party," Andres Felipe Arias, a former Uribe ally, said, referring to the date of the presidential inauguration. "You do not confront the challenge of the guerrillas with mimes and sunflowers."

Mockus responds that he will continue to use the armed forces, which have received training and funding from Washington, to battle the rebels and drug-trafficking in the world's biggest cocaine-producing country. "My philosophy is not to stop things unless there's a sign of something being unproductive," he said.

As mayor of Bogota, a city of 8 million, he invested heavily in police and instituted new tactics, resulting in a dramatic drop in homicides and winning public praise from Uribe.

Mockus also refused to parcel out posts to supporters or meet with municipal officials and council members known for corruption. He raised taxes on the rich and instituted unpopular measures such as closing bars at 1 a.m. to cut down on drunken driving and violence. (It worked.)

What he said he cannot fathom, though, is obtaining results at any price. He referred to one scandal that has plagued the Uribe administration since 2008: the killing of peasants by army units looking to beef up combat death statistics and win favor with their superiors. "That is an act that reflected on the deterioration of the morals of a part of society," Mockus said.

Instead, he often speaks of the sanctity of life, leading followers in chants of "Life is sacred. Life is sacred." He said that Colombians, after years of war, must learn how to stop hating.