New York Times: The oil spill spreading through the Gulf of Mexico has been declared the worst environmental catastrophe ever in the United States. But for American environmentalists, the distress may also bring opportunity. Environmentalists are using the oil spill as a backdrop for fund-raising and to focus attention on related issues. “As Rahm Emanuel says, a disaster is a terrible thing to waste,’ said Zygmunt J.B. Plater, a law professor at Boston College, paraphrasing a 2008 comment by …