By James Painter
BBC Latin America analyst
By any standard, Evo Morales' victory, if confirmed officially, would be historic.
Bolivia is the country in South America with the highest number of people - around 65% - who define themselves as Indians. But it has never had an indigenous president.
Evo Morales' programme for change is radical
Mr Morales would also be one of the very few indigenous presidents to have come to power in Latin America in the last 200 years.
More importantly for Bolivia's political stability, he would be the first Bolivian president to have won such a commanding majority since the country's return to democracy in 1982.
That should give him a strong mandate to push through his reform programme, and also make the country more governable after several years of instability.
Some analysts are already saying that one of the reasons for the unexpectedly high vote in Mr Morales favour, is that many Bolivians would prefer to see him in power than constantly organising protests and blockades against the government.
However, he would face a number of powerful obstacles.
His programme for change, at least as he explained it before the elections, is certainly radical, and is bound to provoke opposition from Washington, the Bolivian private sector, particularly in the east of country, and the large number of oil and gas companies who have invested hundred of millions of dollars in the country.
He has repeatedly said he is in favour of legalising coca, the raw material for cocaine, but not cocaine itself.
That is bound to set him on collision course with Washington which has spent millions of dollars in the last 20 years trying to get Bolivia - the world's third largest producer of coca - to eradicate most of its coca.
Mr Morales says he wants to use coca production for industrial and medicinal purposes, but promises "zero tolerance" for cocaine.
He is very unlikely to continue to implement any US-supported crackdown on coca growing, as one of the most important bases of his support are the coca-growers.
If, as some Washington-based analysts predict, coca cultivation booms, Washington may decide to "declassify" Bolivia as a country collaborating with the US in the fight against drugs.
That in turn could mean Bolivia losing out on millions of dollars of aid both from Washington, and even from international financial institutions.
Unlike Mr Morales' ideological soul-mate, President Hugo Chavez of Venezuela, he cannot count on vast reserves of oil money.
Bolivia remains the poorest country in South America. Even though it has huge reserves of natural gas - the second largest in South America - so far they have not been used to pull Bolivia out of poverty.
A key development to watch is what Mr Morales would do to the oil and gas sector.
He has spoken often of nationalising the sector, but most analysts agree that by that he probably means not expropriation but renegotiation of the contracts with oil companies, higher taxes for those companies, and more state control over production levels and prices.
Even though Mr Morales is more like Mr Chavez of Venezuela in his ideology and gut instincts, the reality of power may force him to be more like the pragmatic President Lula of Brazil
The companies, which include Total, British Gas, and Repsol could decide not to invest any new money, and/or to take the Bolivian state to international arbitration.
Either way, that would mean a delay in much-needed investment in the sector.
Finally, many of his supporters want a new constituent assembly to give more rights to the indigenous majority. It is not clear if he will have the necessary two-thirds majority in congress to push through that reform.
Mr Morales may have several weeks of breathing space, but more radicalised sectors of the Bolivian left would go out on the streets if they thought Mr Morales was not being radical enough.
So Bolivia is probably in for a bumpy ride. And even though Mr Morales is more like Mr Chavez of Venezuela in his ideology and gut instincts, the reality of power may force him to be more like the pragmatic President Lula of Brazil.