WASHINGTON - In a major anti-pollution ruling, the Supreme Court on Tuesday backed federally imposed limits on smokestack emissions that cross state lines and burden downwind areas with bad air from power plants they can't control.
The 6-2 ruling was an important victory for the Obama administration in controlling emissions from power plants in 27 Midwestern and Appalachian states that contribute to soot and smog along the East Coast.
It also capped a decades-long effort by the Environmental Protection Agency to ensure that states are good neighbors and don't contribute to pollution problems elsewhere.
The rule upheld Tuesday was EPA's third attempt to solve the problem.
The rule, challenged by industry and upwind states, had been cast by foes as an attempt by the Obama administration to step on states' rights and to shut down aging coal-fired power plants.
Opponents said the decision could embolden the agency to take the same tack later this year when it proposes rules to limit carbon pollution.
EPA Administrator Gina McCarthy has said the agency will be flexible and work with states on the first-ever controls on power plants for the gases blamed for global warming.