Correction: Earlier versions of this article misstated the first name of a writer at the newspaper El Universal. He is Roberto Giusti, not Luis Giusti. This version has been corrected.

For 12 years, President Hugo Chavez has dominated Venezuela, forging an almost mystical connection with his followers, marginalizing political rivals and accumulating power as he brought every state institution under his control.

Blessed with charisma and funded with billions in petrodollars, he pledged to rule for decades. And few in Venezuela, whether friend or foe, could envision a political landscape without him in the central role he has held since taking office in 1999 and embarking on a self-styled revolution to create a socialist state.

But now, after astonishing his countrymen by revealing that he had a cancerous tumor, the 56-year-old former paratrooper appears vulnerable. Gone is the indomitable combatant who has rolled over political opponents and emerged victorious when defeat seemed certain, as when he was briefly overthrown in 2002.

Instead, the Chavez who went public Thursday about his condition, after nearly three weeks of intensive medical care in Cuba, sounded like a humbled man, telling a national television audience in his country of the “fundamental errors” he had made in not watching his health.

“Without a doubt, what a fundamental error, especially in a revolutionary with some modest responsibilities,” Chavez said in an uncharacteristically short speech from Cuba, where he has been in seclusion with doctors, his aides and top Cuban officials, including Fidel Castro.

Quite suddenly, Venezuelans have begun to consider the possibility that the man who once vowed to rule the oil-rich nation well past 2020 might not even run in next year’s presidential election — in which he has already announced his candidacy.

Carlos Ayala, a constitutional and human rights lawyer who opposes the president’s policies, said he gleaned much from the speech. To him, the boisterous, energetic and unflappable leader who gives speeches lasting seven hours and revels in the fight sounded guarded, even shaken, as he read a prepared text for 13 minutes.

“He looked weak,” Ayala said. “And he looked like everybody looks when they’ve been through major surgery, and he looked more reflective and less passionate as we are accustomed to seeing him.”

Chavez has not said what kind of tumor doctors in Havana removed. Nor has he given details about the treatment he is receiving. He did speak on Friday, though, of continuing with his life’s work, accelerating the transformation of Venezuela.

“No one expected this illness,” he said in a phone call to “Round Table,” a program on Cuban state television. “But we are overcoming, living as before. This will make us stronger.”

Quite human after all

Chavez’s closest associates, some of whom expressed surprise about the gravity of his condition, tried to assure Venezuelans that it was still business as usual and that Chavez would run in 2012.

Vice President Elias Jaua spoke Friday of moving forward on housing programs and “deepening the revolution.” Others in the state apparatus, among them Gen. Henry Rangel Silva, a member of Chavez’s inner circle who met with him in Havana last week, said Chavez was recovering fast.

“He will be in our country soon,” Rangel Silva said.

Luis Vicente Leon, who directs the Datanalisis polling firm and has frequently predicted Chavez’s electoral victories, said the government is grappling with a reality it has never dealt with before — that the leader presented to the poor masses as an almost super-human savior is, after all, quite human.

“There is a political rationale to all this — it is not beneficial for him that the people know he is sick,” Leon said. “The vision of a sick man is not good, not for someone like Chavez, who draws strength from cementing ties with the people.”

Venezuela was a deeply unequal society with a corrupt two-party system when Chavez came to power. He was able to tap into the frustrations of the poor, who lived in misery, boosting his support through massive spending on social programs.

Chavez is known as a frenzied micromanager who jets to the Middle East or Buenos Aires and returns in time to give a five-hour speech, often laced with warnings about American imperialism. Fueled by cups of strong Venezuelan coffee, he works long days, sometimes lasting 20 hours, overseeing the military, mapping plans for socialist experiments and directing economic policies.

After so many years in power, during which moderate mentors and onetime equals broke away, Chavez has become irreplaceable to the loyalists who are left, said Roberto Giusti, a veteran political writer at El Universal newspaper. “It is a regime, a government with a power structure based on one person,” Giusti said. “Everything revolves around Chavez. Chavez is the sun for a solar system around which the planets and moons circle.”

‘This can be positive’

Still, across the country’s social and political spectrum — from critics who call Chavez a classic Latin American authoritarian to leftist intellectuals to his red-clad followers in the barrios — there are now whispers about how things may be different, even if the president makes a recovery.

Nicmer Evans, a political analyst close to the government, said those who support “the fight against imperialism and for a substitute for the capitalist model” need to consider the possibility of another leader if they want to see Chavez’s work completed.

“I think it is important to believe in our country,” Evans wrote in his blog. “Capable people exist within the revolutionary process.”

Nelly Baric, 46, who works in a hospital and helps lead a neighborhood association that receives government assistance, said she “cried and cried” when Chavez announced his illness. But as an activist who believes in his policies, she said, she felt it was time for the president’s allies to consider filling his shoes, if need be.

“This situation should be a call for all of us Venezuelans to reflect, especially for those of us who believe in the revolution, because this transformation cannot continue to be based on one person, just one single man,” she said. “We should be responsible and assume Venezuela’s destiny.”

Opponents such as Margarita Lopez Maya, an academic who once had affinity for Chavez’s efforts to alleviate poverty but who later distanced herself over his governing style, said she could see the potential for a new, more civil political scenario upon Chavez’s return.

“Cancer is hard to deal with, and there is no way he can come back and govern the way he has always governed,” she said. “This can be positive for the country.”

The vice president, Jaua, a former student radical who is a member of Chavez’s inner circle, seemed to suggest the possibility of a softer, more gentle Chavez.

“The world knows a Chavez, shall we say, always in combat,” Jaua said Friday in an interview with Colombia’s W Radio. “But those of us who have known President Chavez for more than 15 years are not surprised by the serene, reflective man who is profoundly human.”

Liebendorfer reported from Bogota, Colombia.