Barack Obama,
Presidential memorandum — State of California Request for Waiver Under 42 U.S.C. 7543…
(2009)
“ California may also adopt standards for new motor vehicles if the Administrator of the EPA, based on criteria set out in the statute, waives the general statutory prohibition on State adoption or enforcement of emissions standards. Other States may adopt emissions standards for new motor vehicles if they are identical to the California standards for which a waiver has been granted and comply with other statutory criteria. ”
