I'm not sure how they will rule. It is clearly unconstitutional. The 5th Circuit Court was correct in stating --

"After the President voiced his displeasure with the country’s vaccination rate in September,12 the Administration pored over the U.S.Code in search of authority, or a “work-around,”13 for imposing a national vaccine mandate. The vehicle it landed on was an OSHA ETS. The statute empowering OSHA allows OSHA to bypass typical notice-and-comment proceedings for six months by providing “for an emergency temporary standard to take immediate effect upon publication in the Federal Register” if it “determines (A) that employees are exposed to grave danger from exposure to substances or agents determined to be toxic or physically harmful or from new hazards, and (B) that such emergency standard is necessary to protect employees from such danger.” 29 U.S.C. § 655(c)(1).

As the name suggests, emergency temporary standards “are an ‘unusual response’ to ‘exceptional circumstances.’” Int’l Chem. Workers, 830 F.2d at 371 (quoting Pub. Citizen Health Rsch. Grp. v. Auchter, 702 F.2d 1150, 1155 (D.C. Cir. 1983)). Thus, courts have uniformly observed that OSHA’s authority to establish emergency temporary standards under § 655(c) “is an ‘extraordinary power’ that is to be ‘delicately exercised’ in only certain ‘limited situations.’” Id. at 370 (quoting Pub. Citizen, 702 F.2d at 1155).14

But the Mandate at issue here is anything but a “delicate[] exercise[]” of this “extraordinary power.” Cf. Pub. Citizen, 702 F.2d at 1155. Quite the opposite, rather than a delicately handled scalpel, the Mandate is a one-size fits-all sledgehammer that makes hardly any attempt to account for differences in workplaces (and workers) that have more than a little bearing on workers’ varying degrees of susceptibility to the supposedly “grave danger” the Mandate purports to address.

13 On September 9, 2021, White House Chief of Staff Ron Klain retweeted MSNBC anchor Stephanie Ruhle’s tweet that stated, “OSHA doing this vaxx mandate as an emergency workplace safety rule is the ultimate work-around for the Federal govt to require vaccinations.” See, e.g., Pet’rs Burnett Specialists, Choice Staffing, LLC, and Staff Force Inc.’s Reply Brief at 4 (emphasis added).

14 The Agency has thus conceded in the past that “[t]he OSH Act does not authorize OSHA to issue sweeping health standards to address entire classes of known and unknown infectious diseases on an emergency basis without notice and comment.” See Department of Labor’s Resp. to the Emergency Pet. for a Writ of Mandamus at 33–34, In re AFL-CIO, No. 20-1158 (D.C. Cir. May 29, 2020) [hereinafter OSHA D.C. Circuit Brief].

It's an abuse of power. If Kavanaugh and SCOTUS disappoints and rules against us, it doesn't end there. We will fight to the last breath and end the OSHA's Temporary Emergency Standard (ETS).