In what has become a highly visible challenge to the EPA’s authority under the Clean Air Act, the D.C. Court of Appeals heard oral argument on April 16, 2015. The case is being viewed by some as a fundamental test of executive authority and the judiciary’s willingness to evaluate and rein in possible overreach. Is the rule, now in proposed form, ripe for challenge, at least in part because compliance with the rule requires a great deal of planning and expense even before its adoption? Has the EPA overreached and, if so, will the court intervene? Or has the EPA properly utilized its statutory rulemaking authority for what all parties indicate will be an important change in the way coal-fired power plants are able to operate? -- Featuring: Robert R. Gasaway, Partner, Kirkland & Ellis LLP