There are allegations that the state was stopped; not just by the Bush Administration, but perhaps by President Bush himself.
All of this came out in a series of memos released by a Congressional committee.
The EPA Administrator denied California's request back in December, saying the country needs a unified, federal approach.
Since then, Governor Schwarzenegger and environmentalists have been on the attack. In fact, the state is suing the EPA.
Some see this as solid evidence of White House meddling.
"He seemed to have a lot of whiplash. He kept looking back at his lawyers every two minutes," said Professor Dan Kamen from UC Berkeley Energy and Resources Group.
Kamen testified at a Congressional hearing, on the same day EPA Administrator Stephen Johnson.
Johnson was trying to explain why he opposed California's bid to limit greenhouse gas emissions from cars, even though his staff supported the move.
Now a staff memo released by the House Oversight Committee chaired by California Democrat Henry Waxman concludes interference from the White House is to blame.
That's not surprising to Mark Ross of the Bay Area Air Quality Management District.
"It's a clear case of political science trumping real science. I don't think anybody is too surprised about this," said Ross.
The California plan would have forced automakers to cut greenhouse gas emissions by 30 percent in new cars and light trucks by 2016, with the cutbacks beginning in the 2009 model year.
But the standards could only take effect if the state got a waiver from the EPA.
"I evaluated the data, made the decision. It was the right decision," said EPA Administrator Stephen Johnson on January 24, 2008.
Monday's Congressional memo suggests it was not independent thinking.
The documents contain sworn testimony from high level EPA officials who say Johnson supported granting California full or partial permission until hearing from the White House.
On Monday, an EPA spokesperson dismissed the reports in a statement saying: "distraction-oriented political tactics of the committee will not keep the EPA from moving forward."
Still, Professor Kamen expects the EPA's California decision will be overturned.
"I hope the administrator will be requested to re-evaluate his decision. And its certainly the case with the general election in November so close, and with all the presidential candidates much greener than the current president, that you're not likely to have this stand," said Kamen.
Senator Barbara Boxer has legislation to overturn the EPA's decision that comes up for a committee vote on Wednesday.
Senator Dianne Feinstein issued a statement saying: "this demonstrates incredible arrogance by the White House, to wholly pervert an agency that is supposed to be independent."