Cabello suffered another political setback in 2008 when he lost re-election to the governorship of Miranda state to Henrique Capriles Radonski, now the opposition candidate to Chavez in this year's presidential election.

But Cabello survived, most recently becoming head of the ministry of public works and housing and also of the nation's telecommunications commission.

And he's become convenient to Chavez and the top military echelon.

"Now [Chavez] needs a tough guy who's been with him in the struggle to consolidate power," Noriega said in a telephone interview. "It's a decision imposed by the narcogenerals as an insurance policy for them."

An engineer by education and training at the nation's military academy, Cabello represents a pragmatic, nationalist segment of the PSUV, which Chavez formed in 2007.

The PSUV is widely considered to be made up mostly of hard-core socialist ideologues favored by the Castro brothers. Vice President Jaua belongs to that wing of the party, as does the president's brother, Adan Chavez. Foreign Minister Maduro is also seen as belonging to that group.

Chavez seemed to shunt Maduro and Jaua aside late last year when he announced they would be leaving their posts to run for office in states that have been opposition strongholds: Jaua would be a candidate for Miranda governor and Maduro would vie for the governorship of Carabobo state. A third ideologue, interior minister Tarek el Aisssami would run for the Tachira state governorship, Chavez announced. Gen. Carlos Mata Figueroa, who was replaced as defense minister by Rangel Silva, would run for governor in Nueva Esparta.

Jaua, apparently still jockeying for power, is said to be resisting a run for governor, Venezuelan columnist Bocaranda reported in March. Maduro also is believed not to want to leave his current post, Bocaranda said.

Unconfirmed reports in the past few days by Bocaranda and others said Chavez was prepared to name Maduro as the new vice president.

Maduro, a former bus driver and union leader, was widely assumed to be a front-runner to replace Chavez because of their apparent close relationship. Maduro is often seen in the front row of Chavez's news conferences or accompanying the president on his trips to Cuba for medical treatment.

There are those who still see him as politically viable.

"Maduro cannot be ruled out," Noriega said. "He has exceeded expectations as foreign minister."

Maduro also could prove useful to Cabello and Rangel Silva, particularly in a figurehead role.

"If Cabello and Rangel Silva resort to dirty work to hold things together, Maduro is a guy they can bring in to give a veneer of respectability to the international community," Noriega said, calling it a "junta kind of arrangement."

The Inter-American Dialogue's Hakim also sees the possibility of a civilian figurehead president if Chavez should step down, "with Cabello and Rangel Silva the powers behind the scene."

There's no doubt, analysts agree, that the narcogenerals cannot afford to expose themselves to criminal prosecution under a civilian government that is not friendly to them.

"They're military people," Noriega said. "They're all about holding on to power at any consequences -- and they're going to do that."

Rangel Silva seemed to indicate in a November 2010 interview that the military would not recognize an opposition victory this year.

"The hypothesis [of an opposition government] is difficult," he said. "It would mean selling the country. The people won't accept that. The armed forces won't, and the people even less so."

Rangel Silva later said his comment had been misinterpreted and vowed in an interview with the Univision TV network this year that "we will recognize whoever wins the Oct. 7 elections."

But some observers see the possibility of a coup if Chavez were to die, become incapacitated or lose the election.

Chavez's appointments of Cabello and Rangel Silva "confirm his regime's descent into militant narcoterrorism and increases the possibility of a coup d'etat by a military junta," senior fellow Vanessa Neumann of the independent, nonprofit Foreign Policy Research Institute wrote in January.

Cabello would be part of that scenario, she said.

"Cabello commands far more respect and loyalty from the military than Chavez," Neumann wrote.

Andres Oppenheimer, a noted Latin American journalist and a contributor to CNN en Español, says he sees three possible scenarios in the months ahead: nothing changes; Chavez names a successor; or there's a military intervention if Chavez is incapacitated or dies.