(Reuters) - The United States is watching "crackdowns on the opposition" in Venezuela, President Barack Obama said in a television interview aired on Friday when asked if he considered newly elected Nicolas Maduro to be the country's legitimate president. Maduro, elected in April by a narrow margin, earlier this year accused the United States of seeking to kill opposition leader Henrique Capriles to stir chaos and spark a coup. Maduro's mentor and predecessor, the late Hugo Chavez, was one of the world's most vocal critics of the United States. ...