NORTH BEND, Wash. - John McCain on Tuesday cast Democratic rivals Barack Obama and Hillary Rodham Clinton as latecomers to the environmental battle, saying he would be willing to debate the issue with either of them in the general election to underscore his experience with the issue. "People will trust my stewardship not only because of my background and knowledge, but also my vision for the future," he told reporters during a news conference at a nature center in the foothills of the Cascade Mountains. "They have never, to my knowledge, been involved in legislation nor hearings nor engagement on...