Friday was a big day to get insight into the Supreme Court’s analysis of President Biden’s authority to impose sweeping vaccine mandates. The court began hearing arguments on two cases about vaccine mandates or testing requirements; one for healthcare workers.

Beginning Monday, unvaccinated employees in companies with 100 or more employees are supposed to wear masks indoors at work unless the court blocks the enforcement. “Testing requirements and potential fines for employers don’t kick in until February” reports the Chicago Tribune.

Chief Justice John Roberts said of the cases at hand, “this is something the federal government has never done before” which is indicative of their “casting doubt on the administration’s argument that a half-century established law the Occupational Safety and Health Act, confers such broad authority” writes the Chicago Tribune.

The court’s three liberal justices appear adamant on their support for the rule. Justice Elena Kagan said officials have shown “quite clearly that no other policy will prevent sickness and death to anywhere like the degree that this one will.” Justice Stephen Breyer said he found it “unbelievable” that it could be in the “public interest” to put that rule on hold.

The Chicago Tribune reports it was the first time seven justices chose to wear masks while hearing arguments. Liberal Justice Sonia Sotomayor, who has been diabetic since childhood, chose to take part remotely in her office so as not to risk exposure to COVID-19’s latest omicron variant. Also two lawyers representing Ohio and Louisiana had to give their arguments via telephone after testing positive for COVID.