WASHINGTON — The Supreme Court voted 6-2 to uphold an Obama administration regulation that requires states with coal-fired power plants to reduce the air pollution that drifts across Midwest and East Coast states.“This is a big win for the nation’s public health and a proud day for the agency,” said Gina McCarthy, administrator of the Environmental Protection Agency.The cross-state pollution rule covers 28 states in the eastern U.S. When it was announced in 2011, the EPA estimated that downwind pollution from coal-fired plants triggered more than 400,000 asthma attacks a year and caused 34,000 premature deaths in neighboring states.“Millions of Americans will breathe easier, thanks to the decision today,” the American Lung Association said in a statement.The cross-state rule was designed to deal with a complex regulatory challenge. The Clean Air Act calls for states and the EPA to work together in setting policies to reduce pollution, but some downwind states have bad air because it drifts across their borders from their neighbors to the west.The EPA’s rule required the upwind states that produced the pollution to do more. But Texas and several Midwestern states, joining with the electric power industry, sued to block the rule. Texas, for one, argued that some utilities would shutter plants to comply with the rule, threatening the state’s ability to keep the lights on. They won a 2-1 ruling from the U.S. Court of Appeals for the District of Columbia, which said the EPA regulation went too far.But the Supreme Court disagreed and revived the rule Tuesday in an opinion written by Justice Ruth Bader Ginsburg and joined by Chief Justice John Roberts and Justices Anthony Kennedy, Stephen Breyer, Sonia Sotomayor and Elena Kagan.Ginsburg said the EPA’s regulation was a reasonable means of enforcing the Clean Air Act. Justices Antonin Scalia and Clarence Thomas dissented, while Justice Samuel Alito took no stance.In its arguments before the court, the EPA said the rules were necessary to protect the health and the environment of downwind states. East Coast states in particular are vulnerable to pollution blown by the prevailing winds of the United States.In her decision, Ginsburg noted that by reining in interstate pollution, regulators must account for the vagaries of the wind. “Some pollutants stay within upwind states’ borders, the wind carries others to downwind states, and some subset of that group drifts to states without air quality problems,” she wrote, adding a biblical quotation from the Book of John: “The wind bloweth where it listeth, and thou hearest the sound thereof, but canst not tell whence it cometh, and whither it goeth.” This report includes material from the Tribune Washington Bureau, Hearst Newspapers and The New York Times.