Gustavo Petro, who topped voting tallies with 40.8% in Colombia's first round of presidential elections on Sunday, has said his political awakening came when he watched his father weep over the death of Argentinian revolutionary Ernesto 'Che' Guevara.
The 62-year-old senator and former mayor, who was part of the M-19 guerrilla group in his youth, hopes to sway millions in a June second round to become Colombia's first leftist leader in decades.
Petro, who is running for president for the third time, has rejected populist characterizations of him by critics and attracted support on his generous social spending promises.
His potential administration "is not a minority oligarchy governing Colombia, it's a multicolor democracy," Petro told a recent rally. "We cannot allow it to slip between our fingers."
Standing between Petro and the presidency is eccentric business magnate Rodolfo Hernandez, who unexpectedly took 28.2% of votes on Sunday.
Hernandez, who already has the backing of third-place candidate Federico Gutierrez and probably many of his supporters, will likely be a tough challenger for Petro.
Surveys ahead of the first round showed the two men just points apart in a second vote.
In historically conservative Colombia, many are concerned about a potential victory by Petro, who first gained national recognition with impassioned congressional speeches about corruption and violence committed by right-wing paramilitary groups and their political allies.
The candidate wants to hike taxes on owners of large tracts of unproductive land and begin to wean Colombia off income from oil and coal, which he has described as poisons comparable to cocaine, perhaps Colombia's top illegal export.
While Petro was never a combatant in the M-19, which in 1985 took top judges hostage in a confrontation that left almost 100 dead, his years in the movement still leave him open to attacks by opponents, who have also belittled his taste for designer shoes.
His 2011 election as mayor of capital Bogota was seen by many as proof that rebel movements like the Revolutionary Armed Forces of Colombia (FARC) could transition to politics.
The FARC laid down their arms under a 2016 peace deal. Petro has said he will fully implement that accord if elected and seek the demobilization of the still-active ELN rebels.
Petro, a father of six, has also pledged low-cost loans for small businesses, free public university education and a redistribution of pensions. He also plans a shift in Colombia's relationship with top ally the United States, away from anti-narcotics policy and toward the fight against climate change.
Petro has promised not to expropriate assets and scoffed at critics' comparisons of him to deceased Venezuelan President Hugo Chavez and successor Nicolas Maduro.
Though left-wing parties won some 50 seats in Congress in March legislative elections, he would likely be unable to pass major reforms without support from centrist parties.
(Reporting by Luis Jaime Acosta; Writing by Oliver Griffin; Editing by Chizu Nomiyama and Christopher Cushing)
