On the campaign stump, Evo Morales liked to say that if he was elected president of Bolivia, he would become America's nightmare. After his election on Sunday, a State Department official said essentially the same thing, calling Mr. Morales "potentially our worst nightmare."

The Bush administration says it fears that Mr. Morales will follow through on his promise to join Hugo Ch�vez, the Venezuelan president, as an anti-American, leftist leader, while also carrying out his promise to reduce restrictions on his nation's production of coca leaf, the primary ingredient of cocaine, much of which finds its way to the United States.