File photo of downtown Los Angeles skyline from Hollywood, CaliforniaBy Lawrence Hurley and Valerie Volcovici WASHINGTON (Reuters) – The U.S. government's authority to keep watch over air air pollution nationwide, frequently towards the desires of Republican-leaning states, could face new curbs when the Supreme Court takes on two excessive-stakes cases in coming months. The circumstances focus on the extensive-ranging power wielded with the aid of the Environmental Protection Company (EPA) beneath the landmark Clean Air Act, first enacted in 1970. The legislation was anticipated as a cooperative effort between the federal govt and states wherein the EPA sets standards however states need to set plans to comply. That flexibility has allowed states which prefer looser rules, like Texas and Kansas, to withstand – with the toughen of business groups just like the U.S. Chamber of Commerce and the National Association of Producers – when the company needs to impose extra stringent standards.