Interesting, I was going off the NYT summary when the news broke:

Forty years ago, when Chevron was decided by a unanimous but short-handed six-member Supreme Court, with three justices recused, it was generally viewed as a victory for conservatives. In response to a challenge from environmental groups, the justices sustained a Reagan-era interpretation of the Clean Air Act that loosened regulation of emissions, saying the Environmental Protection Agency’s reading of the statute was “a reasonable construction” that was “entitled to deference.”

https://www.nytimes.com/2024/06/28/us/supreme-court-chevron-ruling.html