Five years and nine months in the job, Evo Morales has held onto Bolivia's presidency for the longest unbroken period of any elected leader.
Until recently, even rivals acknowledged his role in an unprecedented run of political and economic stability in one of South America's most volatile countries.
But months of anti-government protests and diminishing support among Morales' indigenous base are stirring up doubts about the long-term future of the poor country's first president of Indian descent.
"A build-up of tensions is very quickly eroding the government's influence and credibility, which was the greatest we've had in 50 years," said Roger Cortez, a political scientist at Bolivia's San Andres university.
Leftist Morales, a fierce critic of US foreign policy in Latin America and an ally of Venezuela's Hugo Chavez, has steadily increased the state's role in the economy.
He nationalised the large natural gas industry, mining facilities and utility companies, pleasing the Aymara and Quechua Indians who dominate Andean parts of the country and form the backbone of his support.
At the same time, he has pushed through a series of political reforms aimed at giving the long-neglected indigenous majority a bigger say. In 2009, a new constitution was passed, allowing Morales to keep one of his main campaign promises.
Overhauling the national charter had been a key demand of the social groups that toppled two governments between 2003 and 2005.
Morales, however, has lost his aura of invincibility over the last year as traditional allies have turned against him.
Recent protests against the construction of a $420 million highway through an Amazonian national park and indigenous territory, which were led by Indian activists, prompted Morales to backtrack on Friday.
He said the road would not now be built through the so-called TIPNIS reserve, raising questions about the future of the Brazil-financed project.
Voters punished Morales over the government's handling of the anti-road demonstrations during an election last weekend to vote for national judges.
What was meant to be the latest step in Morales drive to "re-found" the country turned into a major setback when more than half of the voters spoiled their ballots or left them blank.
Opposition leaders had billed the vote as a referendum on Morales' presidency, urging voters to spoil ballot papers in protest over the highway debacle.
Morales' about-face on the road-building scheme follows a similar climb-down late last year when he reversed a dramatic fuel price hike that had unleashed protests across the country, especially among former trade union allies.
Scrapping fuel subsidies and letting prices rise would have saved the state about $500 million per year.
Cortez said that fading confidence in Morales could cause further delays to government-backed industrial and infrastructure projects as he loses his ability to defuse protests by indigenous communities.
Franklin Pareja, a La Paz-based political scientist, said Morales may be paying the price for making generous concessions to small indigenous groups, particularly the right to be consulted on development projects.
"He didn't think being magnanimous would cause him so many problems," Pareja said.
Morales, who has no clear political heir, has hinted that he would like to run for a third presidential term in 2014. But critics say it looks too late for him to get his presidency back on track.
"Morales' time is finished," said Rafael Quispe, an Aymara Indian like Morales and a leader of highland activists who joined the Amazon road protesters.
"This breakdown is basically a result of government arrogance. The social movements just don't trust Evo anymore, and it won't be easy for them to believe in him again," he said.
Besides his turnaround on the Amazon highway route, Morales has given other signs of trying to move beyond these problems since Sunday's judicial election setback.
Communications Minister Ivan Canelas said on Wednesday that, "The country needs reconciliation ... and the government is totally committed to that."
Such an approach would be a novelty for a government that has painted its critics as enemies and tacit recognition of what Pareja described as a "loss of credibility and, of course, the people's disappointment."