The Court of Appeals for the District of Columbia threw out a lawsuit that challenged the Environmental Protection Agency’s proposed Clean Power Plan Tuesday, saying that because the rule isn’t yet in its final stage, it’s too soon for court challenges.

“They want us to do something that they candidly acknowledge we have never done before: review the legality of a proposed rule,” Judge Brett Kavanaugh wrote in the opinion. “But a proposed rule is just a proposal. In justiciable cases, this Court has authority to review the legality of final agency rules. We do not have authority to review proposed agency rules.”

This ruling wasn’t unexpected. When the court heard the case in April, the three presiding judges made it clear that they were skeptical of the requests to act on a rule that was in its proposal stage.

“Do you know of any case when we have stopped rule-making? Why would we do that?” Judge Thomas Griffith asked Elbert Lin, an attorney for West Virginia, during the proceedings in April.

The three judges that threw out the lawsuit were staunchly conservative, which means if another lawsuit is filed against the rule, it will likely be met with a more moderate panel. The decision on that future suit will be based on the merits of the final rule, rather than on the fact that the judges can’t review the legality of a proposal.

The dismissed lawsuit was a combination of two challenges brought against the rule — one from a group of energy companies led by coal company Murray Energy Corp., and the other from a group of 15 states led by coal-heavy West Virginia. The states argued that the EPA didn’t have the authority to regulate carbon dioxide from power plants, and the Murray Energy suit requested that the Court move to prevent the EPA from implementing the “disastrous” rule.

“This is clearly an illegal attempt by the Obama EPA to impose irrational and destructive cap-and-tax mandates, which Congress and the American people have consistently rejected,” Gary M. Broadbent, assistant general counsel and media director for Murray Energy, said in a statement in 2014, when the lawsuit was filed. “These proposed rules will cause immediate and irreparable harm to Americans, including our citizens on fixed incomes and our manufacturers of products that compete in the global marketplace.”

The EPA’s proposed Clean Power plan seeks to cut carbon dioxide emissions from power plants by 25 percent from 2005 levels by 2020 and 30 percent from 2005 levels by 2030. The final version of the rule is expected this summer.

The rule may be safe for now from Murray Energy and the 15 states’ challenges, but this is far from the last time we’ll see the regulation challenged. It’ll likely face more legal challenges after the final rule is released, and many in Congress are working to undermine it through legislation and budget proposals. States, too, could present a major obstacle for the rule — states are supposed to come up with their own plans for implementing the regulation, but several have promised to fight it.

Still, environmental groups heralded the judges’ dismissal.

“Today’s decision by the U.S. Court of Appeals is both a big win in protecting our communities and families against the massive carbon pollution from power plants and an important victory for a fair and democratic rule-making process,” Vickie Patton, the general counsel for the Environmental Defense Fund, told National Journal.