As expected, the Trump administration said today it would re-open review of tough federal mpg and emissions standards that had been finalized under the Obama EPA.

For the past few months clouds have been brewing over what the New York Times reported could lead also to an attack on California’s right to set its own clean air rules, and advocates have been lining up to preemptively counter the perceptive attack.

Under the new U.S. EPA administrator Scott Pruitt, who like Trump questions man-made climate change, the agency will allow automakers another year to make their case on why rules should be weakened.

At present, federal Corporate Average Fuel Economy (CAFE) rules call for an ostensible “50 mpg” or more on average by 2025, although that is done under simplified testing, and the real number on window stickers may average in the high 30s. Today the average is about 25-26 mpg.

A White House official told reporters today that the carmakers doing business in the U.S. were right to decry what was perceived as a power play by the Obama administration. Under Obama’s orders, the EPA moved ahead of an April 2018 deadline to lock in final determination of a “midterm review” for 2022-2025 rules.

A total of 18 automakers had petitioned Trump to reconsider, and as a letter by the Auto Alliance to Pruitt observes, they feel they were handled improperly.

Excerpt from a letter by the Auto Alliance to Scott Pruitt, Trump’s new EPA administrator who has a history of opposing the EPA in his prior career.

Meanwhile environmental and consumer advocates have said they want a “place at the table” in what may be an intense struggle between ideologically and politically divided factions.

Among those wasting no time to comment today was Shannon Baker-Branstetter, policy counsel for Consumers Union.

“The Administration should reconsider today’s action. The EPA finalized the standards after a thorough study of costs and benefits,” said Baker-Branstetter. “A decision to withdraw the standards is nonsensical, as it would merely funnel more money to oil companies at consumers’ expense and halt the progress that can be made in both savings for consumers and vehicle efficiency. The standards already take the cost into account, and the record shows that they are a reasonable, cost-effective approach to improving fuel efficiency and lowering consumers’ expenses.

“EPA conducted a robust review of these standards for nearly two years, taking into account the input from automakers, including thousands of pages of technology and cost assessments, and concluded that the standards were appropriate,” Baker-Branstetter continued. “By rejecting the EPA’s final determination now, its new Administrator is signaling the agency plans to weaken the standards instead.”

As for California, Mary Nichols, chairman of California’s Air Resources Board said she would consider fine-tuning rules to a point.

“We’re not going to refuse to participate in the newly-reopened review process,” Nichols said in a phone interview. “We’ll be there and we’ll be active.”

This said, Nichols does not believe California should be expected to cease its own stance in favor of clean vehicles.

How things might affect Tesla which defiantly stands as an all-electric carmaker also remains to be seen.

“We have the technical and legal ability to run a program that recognizes where electrification of vehicles is headed,” she said. “We’re trying to put together a mix of incentives and regulations to move the entire industry in this direction. This is what we’re going to do.”

It is believed a major legal fight will ensue if Trump makes an unprecedented attack against California. The state – which influences as much as 30 percent of the U.S. car market – otherwise does stand as a de facto rulemaking body. Automakers recognize this, and the Trump administration does too, so even if EPA rules were reduced, carmakers would still have to design, market and sell vehicles made for California rules.

SEE ALSO: Will US Consumers Benefit From Strong MPG Regulations?

That, to some, is a threat that will need to be eliminated, though today’s announcement did not touch on this.

But while others have called the Trump EPA’s initiative an attack, a moderate tone is otherwise being issued. Automotive News reported U.S. Rep. Debbie Dingell, a Michigan Democrat and former GM executive said carmakers don’t want to gut EPA rules.

Rather, the review will allow automakers to air views they feel they were deprived of initially by Obama’s heavy handed maneuver to lock in rules before leaving office.

This story that touches on hundreds of billions of dollars, and that stands to affect the kinds of cars Americans will buy into next decade is only now just beginning.