JOHANNESBURG (Reuters) - A delegation of U.S. congressional Democrats accused the Bush administration on Thursday of blocking plans to alleviate poverty and promote clean economic growth at the U.N.'s Earth Summit. "The U.S. administration is becoming somewhat of an obstructionist in terms of meeting the goals of sustainable development," California Congressman George Miller told a news conference. Talks to cut poverty, increase access to fresh water and promote economic growth while repairing environmental damage run from August 26-September 4 in Johannesburg, a decade after the first Earth Summit in Rio. The Democrats' comments were the latest salvo in their battle...