Governor Bill Ritter is signing what The Denver Post describes as a “landmark clean-air bill,” meant to upgrade aging Front Range coal-fired power plants to run on natural gas. The bill moved fast—17 days—through the state legislature, provoking a battle with some Republicans regarding federal air-quality regulations and how the state’s 2,300 coal-industry jobs might be affected.

But Ritter, a Democrat, found allies in some usual critics: Senate Minority Leader Josh Penry, a Republican, and the natural-gas industry. Mix in environmentalists, Xcel Energy, a majority of Democrats, and looming tougher Environmental Protection Agency air-quality standards, and conditions were ripe for the bill’s passage.

Some Republicans, such as Senator Shawn Mitchell (pictured), a Broomfield Republican, call the measure unfair—“a sweetheart deal for Xcel and the gas companies.”

House Bill 1365 requires cutting up to 80 percent of nitrogen oxides, a pollutant, and preferring burning natural gas over coal.

Several lawmakers, including Penry, co-authored an editorial for the Windsor Beacon on why they favored the legislation, writing that the bill “was a product of bipartisan compromise that grew out of the unpleasant fact that Colorado’s Front Range is out of compliance with federal air-quality requirements. This left policymakers in our state with two options: develop a proactive plan to get Colorado into compliance, or let Barack Obama’s air-quality police in Washington write one for us.”