Detroit News: Republican presidential candidate John McCain said Friday he supports state efforts to limit auto emissions, a stance strongly at odds with the domestic carmakers — and one his campaign tried to refine later in the day. Appearing before about 500 General Motors workers at the company’s technical center, McCain said, “It’s hard for me to tell the states they can’t set their own standards. … At the end of the day, I think states should make their own decisions.” …