Coalition of states , utilities is challenging the government 's authority to limit air pollution . Comment: The government says the tighter rules are an attempt to stem the effects of global warming . Test your knowledge of the Supreme Court . Business groups say regulations are hurting the economy and stifling innovation .
Coalition of states , utilities is challenging the government 's authority to limit air pollution . Comment: The government says the tighter rules are an attempt to stem the effects of global warming . Business groups say regulations are hurting the economy and stifling innovation .