When the senator from Arizona decided to tackle greenhouse gas emissions from U.S. industry, environmentalists were ecstatic: When McCain gets his teeth into an issue, he doesn't let go. (After all, this is the man who won a ten-year battle to reform campaign finance rules.) Now, as chair of the Commerce, Science, and Transportation Committee, his jurisdiction covers just about everything -- from oil tankers to fisheries to the state of our climate. With so many choice tidbits available, he has said that being chair is like being a "mosquito at a nudist colony."