Experts say that the most flexibility that the incoming powers-that-be will have is with respect to last-minute law or those regulations enacted just before President Obama would leave office under the Congressional Review Act. They point to the recent methane rules, which have long been under review but which the Obama administration signed off on in November.

In that case, the administration wants oil and gas producers who operate on public lands to capture methane releases from flaring unused natural gas or those that escape during the piping process. The Obama administration said that it will significantly cut those heat-trapping emissions while also allowing producers to harness the methane for sale to manufacturers and chemical makers. Trump’s team, however, has called the rules onerous and expensive.

The “new regulations are unnecessary, redundant, technically flawed and could stifle the innovations that have led to our nation’s environmental successes,” says Eric Milito, a director for the American Petroleum Institute, in a statement.

While Trump’s team might have luck getting that one tossed, legal experts say that getting the Clean Power Plan will be a much harder fight. That’s because this particular ruling has already wended its way through the court system and is now on its second lap, all over a period of years. The biggest victory as far this regulation has been the one by the US Supreme Court that said in 2007 the EPA could oversee carbon dioxide emissions if they deem such releases harmful to human health and the environment.