LA PAZ, August 10, 2008 (AFP) - As a coca farmer who rose to become Bolivia's first indigenous president, Evo Morales has overcome big obstacles thanks to his indomitable character and his combative nature.

Those traits are in evidence in the referendum he called for Sunday in a bid to reassert his authority over rebellious governors trying to dilute his socialist reforms.

In many ways, Morales, 48, is a reflection of his closest ally, Venezuelan President Hugo Chavez.

Both are capable of stirring rhetoric, both give all to their jobs and leave no time for personal lives -- and both are righteous to the point of dogmatism in their determination to impose nationalistic changes inspired by Simon Bolivar, a 19th century Venezuelan who helped several Spanish colonies in South America win independence.

Born of humble beginnings to an Aymara Indian family in the Andes in 1956, Morales revels in his common touch.

In international meetings, he is easily distinguished in his striped sweater or tie-less jacket and shirt among the costly suits.

When he was a child, four of his siblings died before age two. He was forced by drought to move to a coca-producing area at the start of the 1980s, where he played trumpet in a band and football, both of which allowed him to travel around the country.

He soon became a leader of coca farmers and led a number of protests that served to heighten his profile and his politicization.

He argued vociferously against the US-led campaign declaring coca cultivation to be a narco-trafficking activity because of the leaf's use in producing cocaine. Many of Bolivia's Indians chew the leaf or use it in a brew, believing it has medicinal properties.

In 2002, Morales ran for the presidency but narrowly lost.

The winner, Gonzalo Sanchez de Lozada, lasted only a year in power though before he handed over power to his vice-president, party because of pressure from pressure by Morales's union movement.

In 2005, Morales ran again, and won with nearly 54 percent of the ballots.

He quickly established his 'anti-imperialist' (read: anti-US) credentials and his affinity with Chavez and Cuba's Fidel Castro.

That tie with Chavez, and his refusal to enter into dialog, especially with right-leaning governors, hardened opposition against him.

His main base of support is Bolivia's indigenous population, which makes up 60 percent of the country's 10 million inhabitants.