Green Party presidential candidate Ralph Nader returned to his roots yesterday by launching into a harsh critique of the auto industry, accusing American car manufacturers of blocking advances in fuel efficiency and safety. Speaking to the Economic Club of Detroit, Nader asked, “What is it about this industry, which has such talent and such an obligation to the global environment and to highway safety, that it is constantly putting the brakes on itself unless it is dragged kicking and screaming by government regulators or lawsuits?” He also criticized the Clinton-Gore administration for failing to push through tougher fuel-efficiency rules for automobiles, which would curb pollution and lower the amount of money that drivers spend on gas.