Colorado’s Democratic Gov. John Hickenlooper and Republican Attorney General (AG) Cynthia Coffman are locked in a legal fight over Hickenlooper’s challenge to the AG’s power to act unilaterally on energy and other issues involving the federal government.

Coffman on Friday filed a response at the Colorado Supreme Court asking justices to dismiss Hickenlooper’s challenge, which seeks to get the AG to withdraw from three cases challenging federal environmental regulations.

“Even when the governor and attorney general split along party lines, the AG has not only the authority but also the public duty to seek judicial review to protect the legal interests of Colorado and its people,” Coffman said in her 30-page court filing.

Tensions have mounted between the two statewide officeholders as Coffman has joined other states this year in suing the federal government in high profile energy-related environmental cases, such as the U.S. Bureau of Land Management’s (BLM) proposed hydraulic fracturing (fracking) rules for federal and public lands and a multi-state challenge to the Obama administration’s Clean Power Plan. Hickenlooper contends that he has the exclusive authority regarding these matters.

“In his [Hickenlooper’s] view, even when the attorney general has grave doubts about a question of federal law that will significantly affect the state’s legal interests, she is powerless to seek judicial review absent the governor’s approval,” Coffman said.

“The CPP was one of three suits filed by the attorney general against the federal government without the governor’s support,” a spokesperson for Hickenlooper told NGI on Monday. “The governor understands that the Colorado constitution provides authority to the AG in all sorts of areas, but not in filing suits against the federal government in federal court. To clarify, the governor has not sued the attorney general as her news release suggested.”

Coffman said the court has previously dealt with the same issue and rejected the then-governor’s arguments, which she argued are “substantially identical” to Hickenlooper’s current ones. That case pitted then-Attorney General Ken Salazar, a Democrat, against Republican Gov. Bill Owens. “Because the relevant legal questions presented [now] were resolved in Salazar, this court should not invoke its ‘extraordinary’ original jurisdiction to re-litigate the same dispute,” Coffman said in her filing.

In March, the Independent Petroleum Association of America and the Western Energy Alliance filed a lawsuit seeking to set aside the proposed BLM fracking regulations, and a week later Wyoming filed its own lawsuit, which was subsequently joined by North Dakota and Colorado (see Shale Daily, April 28).

At the time, Coffman raised the legal question of whether BLM could impose its own regulations on fracking, even though federal law does not give it that power and instead allows states to regulate in that area.

“Colorado has robust regulations on oil and gas development, including hydraulic fracturing, and our [state] agency regulators are doing a good job implementing them,” Coffman said in April. “I believe it is important to test BLM’s novel assertion of regulatory authority in an area that has been traditionally — and in this case expressly — reserved for the states.”

According to Hickenlooper’s spokesperson, the governor has the same view, but with a different conclusion, namely that the state can live within the new federal rules.

“Colorado has already made great progress in clean air and clean jobs, and worked extensively with EPA to ensure we have the time and flexibility we need,” Hickenlooper said recently. “We believe that Colorado can achieve the clean air goals set by EPA at little or no increased cost to our residents.”