BY KEVIN G. HALL
  Knight Ridder News Service

  COCHABAMBA, Bolivia - Evo Morales Ayma, an avowed socialist who professes strong anti-American sentiments, was once viewed as a single-issue presidential candidate defending growers of the plant from which cocaine is made. He now threatens to topple Bolivia's troubled pro-U.S. government.

  The deaths of more than two dozen Bolivians in a two-day explosion of political violence last week started the trouble. Then President Gonzalo Sánchez de Lozada's entire Cabinet resigned Tuesday. On Wednesday, he announced severe austerity measures, including the elimination of six cabinet departments, to narrow a budget deficit without raising taxes.

  Morales, who fell just 43,000 votes short of winning the popular vote for president last summer, senses Sánchez de Lozada's vulnerability. Morales' coalition of opposition parties introduced legislation Wednesday calling for an investigation into Sánchez de Lozada's handling of last week's fatal protests. Morales also is organizing protests and calling for new elections.

  ''If I were the president and didn't have the support of the people, I would gladly step down because the people were asking me to resign,'' Morales said at his home outside Cochabamba.

  He is the latest example of a populist leftist resurgence in South America. Populists won presidential elections in Brazil and Ecuador last year, and they lead polls in
  Argentina's April 27 presidential elections. Socialists were elected president in Chile and Venezuela.

  At stake for the United States in Bolivia is $1.3 billion invested in its military, counternarcotics and developmental aid. During his campaign, Morales vowed to kick the U.S. Drug Enforcement Administration out of the country and to legalize the coca plant.

  He sometimes refers to the United States as ``the empire.''

  Morales is an anomaly in Bolivia, where wealthy descendants of Europeans historically have ruled over a population that is 85 percent Indian -- Quechua and Aymara -- and mixed-blood cholos. Morales, an Aymara, leads the Movement to Socialism Party. The name is misleading, because racial issues matter more to him than political ideology.

  ''We need profound change,'' he said. ''We must found the country anew, through a constitutional assembly representing the original nations, and the moment we found this new country we must finish off the old system.'' By that he meant the tradition of patronage among Bolivia's white-minority political and business leaders.

  A nation fairer to its native peoples, he said, would rectify the historic land seizures by the government and industry. It would emulate Cuba's education and health
  systems, he said, and seek greater payments from foreign companies that extract Bolivia's natural gas and minerals.

  Sociologist Arturo Villanueva described Morales as ''still in a process of defining his identity'' as a national leader, and said Bolivians, too, were grasping with his rising power.

  ''There is clear discrimination against leaders with a brown face. There is reluctance to accept him as a leader,'' Villanueva said. ``They view him in the context of coca and his skin color.''

  The son of a poor miner-turned-farmer, Morales, 43, is well spoken and deft, refusing to be pinned down on economic policy and relations with international lenders.

  He won election to Congress in 1997 and was expelled in January 2002 after nationwide anti-government protests that he led turned violent. He was elected again last July. With allies, he controls about a third of the Congress.

  Detractors argue that since he fights for coca growers, he must be paid by traffickers.

  It doesn't look that way at Morales' home. His bedroom is bare, save for a bed, a desk with a computer and lots of photos of himself on the walls.

  Aides have begged Morales to hire security. He responded: ``Only delinquents need bodyguards.''