The fight against President Obama's climate change rules is headed for the Supreme Court, Sen. Joe Manchin said Wednesday after weighing last week's oral arguments in federal appeals court over the centerpiece of the president's plan.

"It's a 50-50" chance that the D.C. Circuit Court of Appeals rules in favor of his state, the West Virginia Democrat said at a hearing he co-chaired in the Mountaineer State on the administration's Clean Power Plan.

West Virginia is leading a group of 27 states in opposing the plan, which limits greenhouse gas emissions from power plants. The states argued against the climate rule during an unprecedented day-long session of oral arguments before 10 judges of the D.C. Circuit court for an en banc review.

"It can be tossed up and go either way," he said. "I think we are going to end up in the Supreme Court, I really do. And we have got to fight hard."

Manchin has been a leading Democratic voice opposing the administration's climate agenda, specifically the Environmental Protection Agency's Clean Power Plan that directs states to cut their greenhouse gas emissions a third by 2030. The emissions are blamed by many scientists for causing the Earth's temperature to rise, leading to more severe weather.

The court's ruling isn't expected until early next year, with the Supreme Court anticipated to take it up much later in the year.

West Virginia and other plaintiffs secured a stay by the Supreme Court in February, which essentially put the EPA plant on ice until all court action concludes.

Manchin joined Sen. Shelley Moore Capito, R-W.Va., who led the field hearing in Logan County. Both senators voiced alarm that the EPA plan has ignored the effect of the climate rules on their state's economy.

Capito said she has been "very frustrated" with the EPA when it comes to their ignoring the effects of the rule on the state.

"One of the most frustrating points for me was in questioning Janet McCabe, who is the EPA acting assistant administrator, about why EPA had not conducted any of their listening sessions in the state of West Virginia when they were drafting the Clean Power Plan," Capito said.

McCabe "basically said, 'well, we went to Pittsburgh,' which shocked me enough, but then she continued. She said, 'EPA wanted to have these discussions in locations where people were comfortable,'" Capito said. "That to me says that they weren't ready to face what we're hearing and going to hear today."

Manchin said he believes the states have a good argument that the EPA plan violates states' rights under the 10th Amendment. The administration is also looking to push out the legislative branch of government by re-interpreting the law as they see fit, he said.

"You can't regulate what hasn't been legislated. The EPA is reaching beyond its legal authority with the rule," he added.

"We have always ridden the market," Manchin said. "We just didn't have the federal government trying to drown us during these difficult times."

Several coal mining companies in the state have declared bankruptcy in the last year, and the added weight of regulation, together with changing market factors, has placed increased pressure on the state's primary industry.

As many as six counties are in a state of economic depression, according to the senators. Capito said a newly released report shows the regulations will cause a $47 billion loss for the state through 2040.

Capito conceded that it's not all the result of the regulations. Low natural gas prices and changing energy markets have had an effect as well. But she said it's safe to say that the bankruptcies were "caused at least in part by regulations."

"Is it all about the regulations? No. It's not all about the regulations," she said. The same can be said about natural gas and market forces. "Each one of those plays a very strong part in what we see happening to our coal industry," Capito said.