Deborah Sivas, an environmental law professor at Stanford Law School, told The Hill that automobile manufacturers are already poised to make the changes outlined in California’s Advanced Clean Cars II rule, which was approved last Thursday.

“They’re going to electric vehicles — they’re just going faster or slower, depending on the philosophy of the company,” Sivas said.

“Congress wanted it to be easy for California to get a waiver, based on what local authorities felt in their judgment,” Sivas said.

While Sivas characterized the legal theories presented in the May lawsuit as “kind of questionable,” she said that there could be an additional lawsuit filed against any future waiver the EPA grants.

“Some folks opposed to the rule could try to directly challenge it on various grounds in state court,” Sivas said. “But I think the most likely and the suit with the most teeth is going to be to challenge the waiver that gets granted. So that’s a federal suit.”