California SB 253 Update – With One Week to Go, Another Swing at a Preliminary Injunction

Viewpoints
November 4, 2026
1 minutes

Yesterday, the Plaintiffs-Appellants in the lawsuit challenging SB 253 and SB 261 submitted a Citation of Supplemental Authorities letter to the Court. The letter cites two recent judicial decisions (included as exhibits) that Plaintiffs-Appellants believe confirm they are entitled to preliminary relief before SB 253’s November 10 reporting deadline. 

The letter and exhibits are available here.

This type of letter submission is a common procedural device in the federal appeals court. It is authorized under Federal Rule of Appellate Procedure 28(j), which allows a party to make a limited submission of supplemental authorities that come to the party’s attention after it has filed its brief. The rule indicates that the submission must be by letter and be no longer than 350 words, hence its format and brevity: “(j) Citation of Supplemental Authorities. If pertinent and significant authorities come to a party's attention after the party's brief has been filed—or after oral argument but before decision—a party may promptly advise the circuit clerk by letter, with a copy to all other parties, setting forth the citations. The letter must state the reasons for the supplemental citations, referring either to the page of the brief or to a point argued orally. The body of the letter must not exceed 350 words. Any response must be made promptly and must be similarly limited.”

The Plaintiffs-Appellants submitted a 28(j) letter about a month ago, in which they asserted: “With the SB 253 reporting deadline now set for next month, covered entities must incur compliance costs now and are under imminent threat of state sanctions if they fail to engage in compelled speech on controversial matters. The need for an injunction is urgent.” See here for that letter.

Meanwhile, the California Air Resources Board is working on its rulemaking for SB 253 reporting next year and beyond, as discussed in this Ropes & Gray post. 

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