Chavismo's undisputed leader will continue to be Chavez, dead or alive.

But many within Chavismo have more fear than respect for the 49-year-old former soldier.

If the president's foes have their way, Chavismo will end the same day his rule does.

After a crushing electoral defeat, Maduro is facing pressure within the ruling party to defend Chavismo.

None have been heavyweight leaders of the leftist "Chavismo" movement forged by his late mentor.

The Chavismo regime, named after Chávez, has governed the country with increasing ruthlessness for the past two decades.

The opposition believes the poll may mark the beginning of the end for the governing "Chavismo" movement.

Two years ago, Smilde said he had little sympathy for the protesters because Chavismo had recently won an electoral mandate.

The furious reaction highlighted Chavismo's sensitivity to even the slightest discussion of succession, which has been expunged from all official discourse.

Late leader Hugo Chavez turned the military into a bastion of "Chavismo" after a short-lived coup against him in 2002.

Chavismo is the movement founded by former President Hugo Chavez, who Mr Maduro succeeded following Mr Chavez's death in 2013 from cancer.

Supporters say he is recovering but insist Chavismo would continue in its current form even beyond him, just with different men leading Chavez's vision.

The volatile situation underscores the challenges of the "Chavismo" movement to maintain Hugo Chavez's self-styled revolution without his messianic but micro-managing leadership.

That has turned the once theoretical debate over "Chavismo without Chavez" into a very real enigma with major political and economic repercussions.

If elected, Maduro vows he will maintain the socialist policies of "Chavismo" in the energy-rich nation, despite rampant inflation and falling oil production.

Opinion polls have shown Maduro as the likely winner, but Chavez's opponents said they wanted a chance to end "Chavismo" at the voting booth.