The Republican effort to repeal California's waivers that allow it to set its own vehicle emissions standards has sparked a complex debate over how the government defines a rule, Nick writes.

Why it matters: Tossing the state's regulations — which effectively ban the sale of new gasoline-powered cars by 2035 — is a major priority for Republicans and much of the auto industry.

Driving the news: Republicans say they hope to use the Congressional Review Act to nix the waiver, likely after Congress' scheduled recess next week.

• That's despite GAO's conclusion that the waivers aren't subject to a repeal resolution.
• "It's still under discussion," Senate EPW Chair Shelley Moore Capito told Nick. "My opinion is that something that's sent up from an agency … is a rule if it's sent up as designated as a rule, which this was."
• Capito and multiple House lawmakers have said they intend to introduce repeal resolutions.

Context: The Clean Air Act lets EPA grant California waivers to set its own vehicle emissions regulations that are more stringent than federal rules, and other states can follow suit.

• The Biden administration used that authority last year to allow California to put out new regulations on cars and heavy-duty trucks.
• But EPA Administrator Lee Zeldin last month sent the Biden waivers to Congress as a formal rule, arguing that they're eligible for speedy repeal under the CRA.

Zoom in: The question is whether the waivers are "rules" that are reviewable under the CRA.

• GAO says they are "adjudicatory orders" as defined by the Administrative Procedure Act and aren't subject to the CRA.
• EPA's action to issue the waivers is "backwards-looking," said Sidney Shapiro, an administrative expert at Wake Forest University School of Law.

Yes, but: Other legal experts argue that EPA's waivers are, in fact, "rules" — and say Congress has the sole authority to make that determination.

• "The fact that every other state in the union can join in distinguishes this from every other adjudicatory order I've ever heard of or seen or that anyone's pointed out in this debate," said Michael Buschbacher, a partner at Boyden Gray.
• His firm has worked on litigation against the waivers.

What's next: Sen. Sheldon Whitehouse, who asked GAO for its opinion, told Nick that the Senate parliamentarian will have to determine "whether it's in order to use a CRA to try to undo an agency decision that is not a rulemaking."

• Republicans could move to overrule the parliamentarian, but "that would be an unusual declaration of war," Whitehouse said.

Between the lines: The CRA bars judicial review, but there's relatively little case law surrounding it, and courts have differing interpretations.

The White House tapped a lawyer who argued against Biden administration environmental regulations to be the Energy Department's next general counsel, Daniel writes.

Why it matters: Jonathan Brightbill argued the West Virginia v. EPA case at the D.C. Circuit that ultimately limited the EPA's efforts to address climate change.

• Brightbill, if confirmed, would be the clearest sign yet of the agency's shift away from issuing major regulations without clear direction from Congress in a post-Chevron world.

Brightbill, as the Justice Department's top environmental lawyer under Trump 1.0, defended EPA's decision to repeal the Obama-era Clean Power Plan and replace it with the Affordable Clean Energy Rule.

• He also argued for the Trump EPA's definition of the "waters of the U.S.," the scope of which the Supreme Court similarly limited in 2023.

Zoom in: President Trump also sent over nominations to lead the agency's electricity office and its nuclear waste cleanup mission.

• Catherine Jereza, a utility industry veteran currently an adviser in the Office of Infrastructure, was nominated to be assistant secretary for electricity.
• Timothy Walsh was tapped to be an assistant secretary for environmental management.

❓ 1. AI RFI: Rep. Julie Fedorchak issued a request for information as she seeks to develop legislation to address the rising demand for power from artificial intelligence.

• Fedorchak said she hopes her AI and Energy Working Group will "craft a legislative framework that secures our energy dominance, strengthens our electric grid, and positions America as the global leader in AI."

🚗 2. EVs cruise-in: Executives from about 22 companies representing the EV and battery supply chain are meeting today and tomorrow with nearly four dozen Capitol Hill offices.

• The meetings, organized by the Zero Emission Transportation Association, comes as the EV consumer tax credit remains a popular target from Republicans in budget reconciliation.

🌽 3. E15 fight: Rep. Adrian Smith and Sen. Deb Fischer will lead a presser this afternoon with the National Corn Growers Association to discuss their legislation to allow year-round sales of a higher ethanol gasoline blend.

• Lawmakers are making a fresh pitch for the bill after it was in the mix in spending legislation in December before being dropped.