(CNN) As the Supreme Court debated federal authority to impose a vaccine requirement on workers, the nine justices could not help but reveal their varying sentiments about the depth of America's Covid-19 pandemic and the value of vaccines.
"We know that the best way to prevent spread is for people to get vaccinated," Justice Elena Kagan said, "and to prevent dangerous illness and death is for people to get vaccinated. That is by far the best. The second best is to wear masks."
That view was not universally shared.
Justice Clarence Thomas, a conservative, took a different tack than liberal Kagan regarding the sweeping rule the Occupational Health and Safety Administration seeks to impose.
"There's been some talk ... that the vaccinations are efficacious in preventing some degree of infection to others," he said, and observed, "As I remember in the filings ... that younger workers, the 20-year-olds who are unvaccinated are actually safer than the older workers who are vaccinated. So there are obviously some differences."
According to the US Centers for Disease Control and Prevention, the risk for death of unvaccinated people is far higher than for vaccinated.
In October, unvaccinated people had a 5 times greater risk of testing positive for Covid-19, and a 14 times greater risk of dying than fully vaccinated people, according to the CDC. Fully vaccinated people can get Covid-19 and spread it to others, but studies have shown they spread it for a shorter period of time than unvaccinated people, which reduces the risk to others.
During the dramatic special hearings that lasted nearly four hours, the conservative-dominated court appeared ready to reject the Biden administration's vaccine-or-test requirement for large employers but perhaps allow a vaccine mandate for certain health workers in Medicaid and Medicare-funded facilities.
The justices' competing vantage points and ideologies -- particularly against broad regulatory powers -- were evident throughout the session.
In more human terms, one aspect did unite most of them, as the highly infectious Omicron variant now rages: the complications of mask-wearing and when to drop it down for conversation. All justices except Neil Gorsuch wore a mask on the bench. Some removed their face coverings when they asked questions, at times fumbling to release them from their ears. Some kept them off longer than others, irrespective of whether they were asking questions.
Until Friday, only Justice Sonia Sotomayor, who has diabetes and has taken extra precautions with her health, had worn a mask during the justices' oral arguments. On Friday her seat was empty, as she participated via a feed from her chambers.
Fellow liberals Kagan and Stephen Breyer kept their face coverings on throughout, posing questions through the filter of a close-fitting mask. Adding to the pandemic atmosphere, two of the lawyers who were set to argue in person against the mandates presented their cases through a remote feed due to Covid-testing protocols.
An overriding question was who decides sweeping safety protocol amid a health crisis. The court led by Chief Justice John Roberts has in recent years tried to curtail the reach of federal regulators, believing that agencies have usurped power that belongs to elected officials.
The Biden administration contends the directive instituted by the Occupational Safety and Health Administration flows directly from its statutory authority to protect workers from viruses that present "a grave danger." Employees who refuse to get fully vaccinated would be required to wear masks and show proof of a negative Covid-19 test once a week.
"Covid-19 is the deadliest pandemic in American history and it poses a particularly acute workplace danger," US Solicitor General Elizabeth Prelogar told the justices. "Workers are getting sick and dying every day because of their exposure to the virus at work. OSHA amassed substantial evidence of widespread workplace outbreaks across industries. It studied the science of how this virus is transmitted and found that workers are exposed to danger when they're inside together for as little as 15 minutes."
But Roberts and other justices on the six-member right wing suggested by their questions that OSHA overstepped its authority, that a vaccine requirement that could affect an estimated 80 million workers should be left to Congress or state authorities.
The give-and-take went beyond the legal particulars of the dispute to expansive questions of policy and the Covid crisis.
Roberts noted that the administration was imposing multiple mandates.
"It seems to me that the more and more mandates pop up in different agencies," he said, "I wonder if it's not fair for us to ask the questions of, well, why doesn't Congress have a say in this, and why doesn't this be the primary responsibility of the states."
He also suggested he was sympathetic to the view that Covid-19 transmission was, as he termed it, "not a workplace issue (but) an out-in-the world issue." Lawyer Scott Keller, representing the National Federation of Independent Business, agreed, telling Roberts, "Instead of doing an economy-wide vaccine-or-testing mandate for all purposes, OSHA needed to at least consider ... those industries where there's a heightened risk," such as health care.
Breyer, the senior liberal on the bench, interjected, focusing on the potential public health consequences of blocking the vaccine-or-test requirement.
"There were three-quarters of a million new cases yesterday. New cases," he emphasized. "The hospitals are today, yesterday, full, almost to the point of the maximum they've ever been in this disease, okay? ... Can you ask us to say it's in the public interest in this situation to stop this vaccination rule? ... To me, I would find that unbelievable."
The NFIB and officials from 27 states who have filed lawsuits want the court to intervene by Monday when part of the new rule would take effect.
All nine justices received their first shots of the vaccine in early 2021. After earlier declining to respond to reporters' questions about whether all had received booster shots, Supreme Court officials this week revealed that all nine had indeed received the vaccine booster.
During Friday's sessions, the justices showed varying regard for the value of vaccines. Taking the opposite approach of Breyer, conservative Justice Samuel Alito raised a potential downside of the shots.
"I don't want to be misunderstood in making this point because I'm not saying the vaccines are unsafe," Alito began. "The FDA has approved them. It says that the benefits greatly outweigh the risks. I'm not contesting that in any way. ... But is it not the case that these vaccines and every other vaccine ... and many other medications have benefits, and they also have risks ... adverse consequences? Is that not true of these vaccines? ... There is a risk, right?"
The CDC says the risks are minimal.
"Serious side effects that could cause a long-term health problem are extremely unusual following any vaccination, including COVID-19 vaccination," the CDC says. "The benefits of COVID-19 vaccination outweigh the known and potential risks."
Emphasizing the vaccine's protection, Prelogar said that "to suggest that OSHA is precluded from using the most common, routine, safe, effective, proven strategy to fight an infectious disease at work would be a departure from how (OSHA's statutory mandate) should be understood."
Kagan quickly added her own rejoinder to Alito: "Can I just say that regulators think of risk/risk tradeoffs constantly when they make regulations ... but one risk vastly outweighs another risk."