The legal battle over the Biden administration’s coronavirus vaccination or testing requirements for private businesses is falling along the country’s sharp political fault lines, with Republican-led states, conservative legal groups and sympathetic employers lining up most forcefully to try to block the rules.

Opponents celebrated a court ruling on Saturday that would temporarily halt the policy. But that was just the opening round in high-stakes litigation that could shift to a different set of judges as early as next week under a little-known judicial lottery system — and end up before the Supreme Court, perhaps before the policy is scheduled to take effect on Jan. 4.

The Louisiana-based federal appeals court that issued Saturday’s order is now considering whether to more permanently halt the new rule, which requires companies with more than 100 employees to either mandate vaccinations or require weekly coronavirus testing and masks for those who work on-site or in person with others.

The Biden administration told the U.S. Court of Appeals for the 5th Circuit this week that the Occupational Safety and Health Administration rules are designed to address “grave dangers posed by covid-19 in the workplace” and will “save thousands of lives and prevent hundreds of hospitalizations.”

The Texas-based airlines said on Oct. 13 that they will require coronavirus vaccinations for workers despite a state executive order banning vaccine mandates. (Reuters)

Blocking the mandate, the Justice Department said, is likely to “cost dozens or even hundreds of lives per day.”

Opponents say the federal government has overstepped its authority and does not have the “power to coerce” more than 80 million Americans “to inject an irreversible vaccine into their bodies, under threat of losing their livelihoods and threat of fines or other penalties,” according to the brief filed by one of the attorneys, Matthew R. Miller of the Texas Public Policy Foundation.

The challengers in the case at the conservative 5th Circuit include a former Republican candidate for the Louisiana House of Representatives who says he opposes the mandate as a business owner and employees at a company owned by a wealthy North Carolina conservative activist, in addition to Christian and conservative legal groups.

At the 5th Circuit, the three-judge panel that issued the temporary order said the challengers give “cause to believe there are grave statutory and constitutional issues” with the mandate.

Other groups of mostly Republican-led states have joined separate challenges filed in at least four different federal appeals courts based in Georgia, Illinois, Missouri and Ohio.

On the other side, the AFL-CIO labor federation and the United Food and Commercial Workers International Union filed a petition on Monday with the more liberal-leaning D.C. Circuit. It is all part of a strategic legal tug of war over the hotly contested issue.

The petitions are expected to be consolidated before a single appeals court as soon as next week, when a special judicial panel will randomly designate one appeals court to handle them together.

Washington lawyer Sean Marotta, who has studied the lottery system, said the 5th Circuit’s order may be short-lived if the case is assigned to a different court. The three-judge panel, he said, may not have been aware of the timeline when it ruled Saturday, or there may have been judges “who have strong theories about the mandate and wanted to make their views known even if they will not have the final word.”

The Justice Department has asked the 5th Circuit to hold off on any further action before the lottery takes place.

OSHA invoked a rarely used emergency power last week when it issued the policy, which is expected to cover 84 million workers. The Biden administration estimates the rules will save more than 6,500 lives and prevent more than 250,000 hospitalizations over a six-month period.

David Vladeck, an occupational law expert at Georgetown Law School, said OSHA was well within its power to issue the rules. But how the agency will fare in court is another question.

The federal government has a strong case, Vladeck said, because the point of the specific act it invoked is “to ensure that workers are safe in the workplace.”

“It’s going to be controversial because it’s covid,” he said. “Not because OSHA has somehow overextended its jurisdiction.”

The federal safety agency largely avoided issuing emergency standards in recent decades, after a string of court losses in the 1970s and early 1980s on emergency rules related to benzene, asbestos and certain pesticides. But Vladeck said that the vaccinate-or-test standard was on more solid legal ground, based on the unique circumstances of the pandemic that so far has killed more than 750,000 people in the United States.

In the other emergency cases, “there was no proof of the kind that exists here,” he said. “There is a public health emergency that needs an immediate response.”

David Michaels, who headed OSHA under President Barack Obama, said opponents of the requirements are portraying them inaccurately, ignoring the option for those who don’t want to get vaccinated to wear masks and get tested regularly.

He pointed to statements from the Liberty Justice Center, a conservative legal advocacy group, which says on its website that the federal government is “mandating COVID-19 vaccines for all Americans who work for private companies with 100 or more employees.”

Brandon Trosclair, the former political candidate in Louisiana whose businesses also sued the federal government, is quoted on the site as saying the mandate forces workers to get a vaccine or be fired.

“They’re trying to pretend that this is a vaccination mandate, to make people angry,” Michaels said.

A spokeswoman for the Liberty Justice Center, which represents Trosclair, said: “The federal government is telling businesses to impose vaccines or testing on their employees. That is a mandate.”

Since August, the Supreme Court has three times refused to stop vaccination requirements: in Indiana, New York and Maine. Justice Amy Coney Barrett, a conservative, rejected a request from Indiana University students. Justice Sonia Sotomayor, one of the court’s three liberal members, declined to halt a New York City mandate for public school teachers. The justices handled the emergency petitions from the regions of the country in their purview without referring the matters to the other justices.

And the full court turned down a request from Maine health-care workers to block a state mandate that does not include an exception for religious objections. Three conservative justices noted their dissent, with Justice Neil M. Gorsuch writing that there should be a religious exemption.

But the legal questions about the administration’s new rules will center on different questions than those cases. They will involve the scope of OSHA’s regulatory power and whether the rules are consistent with its authority.

In some ways, Biden’s policy is more lenient than those imposed by some private companies and states. Many state regulations that apply to health-care workers, for instance, do not give unvaccinated employees the option of frequent testing.

“Not all of these claims are the same and not all of these mandates are the same,” said Wendy Parmet, a Northeastern University law professor who specializes in public health law.

She noted that for decades, states have required certain vaccines for children to attend school and pointed to the 1905 Supreme Court decision upholding state authority to enforce vaccination laws.

At the same time, Parmet said, the current Supreme Court majority is “far more skeptical of regulatory power, public health protection and especially when it implicates religious liberty claims.”