ROCK SPRINGS, Wyo. - This small Western hamlet, best known for a bloody race riot involving white and Chinese coal miners in 1885, might not be the first place one would expect to find the former leader of the free world. But here was Bill Clinton in southwest Wyoming, two days before Saturday's Democratic caucuses, telling about 1,000 people how his wife, Hillary Rodham Clinton, would establish 10 clean-coal technology projects if elected president in November. "Some environmentalists don't think we ought to be doing anything with coal, but they're wrong," he said. "Think about it, you could become, maybe,...