Rep. John McHugh, R-Pierrepont Manor, was among only eight Republicans to vote with Democrats for the American Clean Energy and Security Act, making the difference needed to pass the bill.
McHugh said he decided to support the measure after the bill's sponsors agreed to support parts of his proposal to impose new limits on the pollution that causes acid rain.
McHugh, whose district includes much of the Adirondacks, has worked on the acid rain issue during his nine terms in office.
