When Hugo Chávez anointed Nicolás Maduro to succeed him as Venezuela’s president, few realised that he would become Latin America’s Robert Mugabe.

After all, Maduro had a reputation as a conciliator. He was physically imposing – a big, burly man – but not charismatic and not known for ambition. The former bus driver had limited formal education and gave the impression of rising through the revolution’s ranks – head of the national assembly, foreign minister, deputy president – at Chávez’s behest.

Though raised a Roman Catholic, he was a follower of the late Indian spiritual guru Sai Baba and told the Guardian in 2014 he was a bit of a hippy with a penchant for John Lennon and Led Zeppelin. “Our side is peace, love and tolerance,” he said.

Three years on, that sounds Orwellian. Venezuela is a basket case and Maduro, 54, is on his way to dictatorship. The government has banned protests and mobilised 370,000 troops in advance of today’s vote that opposition leaders say will mark an end to democracy. It comes after four months of street protests and violent repression that have left more than 100 dead, thousands in jail and the country in chaos.

Last week, the airlines Delta and Avianca suspended flights in and out of Venezuela, citing luggage theft and “irregular” fuel quality, among other reasons. The US state department ordered relatives of embassy employees to leave after Washington imposed new sanctions on Venezuelan officials. Colombia is bracing for an accelerated influx of Venezuelans fleeing hunger and desperation.

The country is reeling from power cuts, hyper-inflation, rampant crime and shortages of food, medicine and other basic goods. With foreign reserves evaporating, Venezuela may default on billions of dollars of debt payments. All this in a country with bigger oil reserves than Saudi Arabia.

Instead of trying to negotiate a truce with the opposition or flee, Maduro has doubled down in Miraflores, the presidential palace in Caracas, and cast this as an existential moment.

“We have no other option between winning and dying,” he told a rally outside the palace walls last week. “The oligarchies of the world have reacted because they fear a new Venezuelan constitution. Who do we obey? In Venezuela, the people govern.”

Observers warn that the country teeters on the edge. The crisis has been brewing for years but the immediate flashpoint is Maduro’s decision to hold an election today for a constituent assembly that will have the power to rewrite the constitution and dissolve state institutions.

The opposition has called a general strike and fresh street demonstrations in protest. Maduro responded by mobilising troops and banning public protests, with jail terms of up to 10 years for those who disobey.

The crackdown lays the groundwork for “a new wave of mass human rights violations,” said Amnesty International. It set the stage to perpetuate Maduro in power, said Human Rights Watch. “Most likely, it’s the key to a long-lasting dictatorship that must be stopped before it’s too late.”

Venezuela, once South America’s wealthiest, model democracy, is emulating Zimbabwe. How has it come to this? In person, Maduro can be affable, even charming. The son of a union leader, he began his political career as president of the student union at José Avalos high school in El Valle, a working-class neighbourhood on the outskirts of Caracas. He is remembered as a flexible, pacifying figure who liked to negotiate.

And the movement he heads – chavismo – was once a beacon for the world’s left, a socialist revolution that won elections, empowered the poor and challenged US hegemony in Latin America. It was the red foam of the “pink wave” that took power in Argentina, Brazil, Bolivia, Ecuador and Nicaragua. Jeremy Corybn and Oliver Stone, among others, paid homage.

Few pilgrims do the solidarity tour these days. In leftist circles, Maduro is seen, at best, as an embarrassment – the heir who screwed up Chávez’s legacy.

In leftist circles Maduro is seen, at best, as an embarrassment – the heir who screwed up Chávez’s legacy

In reality, Venezuela’s ruin is rooted in Chávez’s rule, a 14-year melodrama of populist thunder, marathon speeches, televised stunts, creeping authoritarianism and bungled economic policies that ended with the comandante’s death from cancer in 2013. Chávez bequeathed grave problems – and Maduro made them worse. Historians will long debate which man bears more responsibility for the unfolding agony.

After leaving school without a diploma, Maduro reportedly considered joining a rock band before a studying stint in Cuba. Back home, he joined Venezuela’s Socialist League and drove a bus for the Caracas Metro company. He became a union negotiator and, in the early 1990s, a member of the MBR-200, the civilian wing of Chávez’s insurrectional military movement.

Chávez, a former tank commander, was in jail for a 1992 coup attempt. Maduro met and married Cilia Flores, part of Chávez’s legal team. When Chávez won the 1998 election, the duo became a power couple, Maduro rising to head the national assembly, Flores becoming attorney general.

In 2006, Chávez appointed him as foreign minister, a role he performed dutifully for six years, breaking and mending relations with Bogotá, assailing Washington, wooing Tehran, briefing Havana.

Western ambassadors found him to be polite, stolid and rather dull. Chávez at times teased and patronised him. “Look at Nicolás there, handsome in his suit, not driving a bus anymore,” he said, as reporters looked on. But the president trusted him.

As Chávez’s cancer worsened, he named Maduro his deputy and heir. “My firm opinion, as clear as the full moon – irrevocable, absolute, total – is… that you elect Nicolás Maduro as president,” he said in a dramatic, final speech in December 2012. Some wonder whether Maduro really wanted the crown. Either way, he accepted it. Venezuela swiftly discovered a newly garrulous, combative and folkloric Maduro. He claimed Chávez’s spirit visited him in the form of a little bird.

He won a disputed election in 2013, but the slender margin shook the revolution – millions of supporters abstained in protest at economic woes. Two years later, the opposition swept national assembly elections.

Nicolás Maduro greets a dwindling band of supporters in Caracas last week. Photograph: HANDOUT/Reuters

Maduro faced a dilemma. Price and currency controls as well as expropriations and nationalisations withered agriculture, manufacturing and tourism. Tumbling oil revenues made it harder to mask the fiasco.

Changing course meant abandoning revolutionary tenets, alienating ruling factions and negotiating with opponents he branded “faggots”, “imperialists” and “scum”. Not changing course invited disaster. He chose the latter. Cuban levels of impoverishment – doctors earning $20 a month – plus riots and mass looting are the result. Maduro blames traitors and the US.

Maduro’s approval ratings have plunged to around 20%. Foreign allies such as Spain’s Podemos party have recoiled. José Mujica, Uruguay’s former president, called Maduro “crazy as a goat”. Venezuela’s top prosecutor recently broke with the government, the first serious defection.

Yet the former bus driver trundles on. Ideology partly explains it. Maduro is more rigid than Chávez, a late convert to socialism. The comandante did however gift his successor control of all state institutions, including the judiciary and armed forces. Maduro can rely on brute force.

Amid all this the president still hosts a radio show – “It’s time for salsaaaaa! Pay attention, this is the force of happiness.” Surrealism with touches of Nero and Fellini. But he is not crazy. Losing power means, in all likelihood, losing liberty. Byzantine rules have sabotaged the economy while creating opportunities for insiders, siphoning oil revenues into illicit fortunes for military officers and certain government officials, including, it is alleged, relatives of the first family. Venezuela is a major conduit for drug shipments.

Last year, a federal jury in New York convicted two of Cilia’s nephews of conspiring to import 800 kilos of cocaine into the US. If Maduro falls many feel he will be charged with corruption and human rights abuses.

It adds up to a strong incentive to keep gripping the wheel, no matter if he takes Venezuela over a cliff.

Rory Carroll was based in Caracas as the Guardian’s Latin America correspondent from 2006-2012. He is the author of Comandante: Hugo Chávez’s Venezuela

THE MADURO FILE

Born Nicolás Maduro Moros, 23 November 1962, in Caracas, Venezuela. His father was a union leader and he was raised in a working-class neighbourhood. He did not graduate from high school. Married with one son. Worked as a bus driver before entering politics.

Best of times He rose quickly under the sponsorship of Chávez, becoming minister of foreign affairs in 2006. He was chosen by Chávez in 2011 to succeed him and, on Chávez’s death, became president in 2013.

Worst of times Chaos has reigned for much of his presidency and he has ruled by decree for most of the time.

What he says “They inoculated Commander Chávez with that illness to get him out of the way and create a situation of destruction for Venezuela and its independent revolution.”

On a foreign power infecting Chávez with cancer.

What they say “Backing down now would make Maduro look very weak among the elites and the military.” Jason Marczak, of the Atlantic Council’s Latin America centre.