The Supreme Court on Tuesday sided with conservatives seeking to delay the enforcement of President Obama's Clean Power Plan.
In a five to four decision (with all four liberal justices dissenting), the court agreed to halt enforcement of the plan until its legal challenges are resolved.
The decision is a huge blow for President Obama, who last August called the Clean Power Plan "the single most important step America has ever taken in the fight against global climate change." The plan would impose carbon dioxide emissions limits on existing power plants. Already, the administration has imposed carbon limits on future power plants, but this is the first time such limits would be applied to existing ones -- the single largest source of carbon pollution in the U.S.
Conservatives and those with an interest in fossil fuels have vigorously oppose the plan on economic grounds. Senate Minority Leader Mitch McConnell, R-Kentucky, once called it "a dagger in the heart of the American middle class." Several states and industry groups have been fighting the plan in court.
In a late-night call Tuesday, administration officials called the decision "extraordinary" and "unprecedented," and insisted that they remain confident the administration's argument will prevail in court when the case is decided on the merits. This decision is a "temporary, procedural determination," one official said, and it doesn't affect the administration's confidence in the legal soundness of the overall rule.
"When it gets its full day in court and the court evaluates this on the merits they will see that we are right," one official said.
Defending the Environmental Protection Agencies actions, the officials said that the rule was crafted after an extensive public comment process, and the approach that was ultimately adopted is already in place in many places across the country.
And while they admitted they were "surprised" by the court's decision, they acknowledged that "we always assumed this rule would be litigated" as it worked through the planning process.
The officials insisted that this determination will not affect the implementation of the breakthrough Paris climate agreement.
President Obama was briefed on the ruling, the officials confirmed, but officials said it would not stop him from using his executive authority in other ways over the course of his last year in office.
"I think that the president has undertaken to do bold things but always within the parameters of his authority and while that's certainly triggered a good deal of litigation, that litigations' going to play out," one official said, adding, "because he's confident in the advice he gets from the Department of Justice on the legality of his actions, he's going to continue to do what he thinks needs to be done to help the American people."
States aren't expected to comply with the new Clean Power Plan limits until 2022, but they are expected to submit their plans for compliance by September.
The Environmental Defense Fund, which is a party to the case, stressed in a statement that the court's decision Tuesday to halt the plan's enforcement "does not reflect a decision on the merits" of the plan itself. The Washington, D.C. Circuit Court is slated to review the merits of the lawsuits challenging the Clean Power Plan on June 2.
"The D.C. Circuit court will carry out a careful and expeditious review of the merits over the next few months," Vickie Patton, general counsel the Environmental Defense Fund, said in a statement. "The Clean Power Plan has a firm anchor in our nation's clean air laws and a strong scientific record, and we look forward to presenting our case on the merits in the courts."
The DC Circuit Court will begin hearing oral arguments on the merit of the EPA clean power plan in June.
CBS News Producer Adam Aigner-Treworgy contributed to this story.