MEXICO CITY (Reuters) - Robert Zoellick, almost certain to be the next head of the World Bank, on Saturday took aim at Venezuela's leftist president, Hugo Chavez, warning that his oil-fueled socialist revolution was headed for trouble. "It's a country where economic problems are mounting, and as we're seeing also on the political and press side it's not moving in a healthy direction," Zoellick told reporters during a visit to Mexico.