On Thursday, the president announced a new aggressive stance towards vaccination regulation that will impact federal contractors, health care, and private sector workers. The sweeping rule change requires all private-sector employers with more than 100 workers to mandate that they get vaccinated or tested regularly, affecting about 80 million people. The 17 million workers at health facilities that receive Medicare or Medicaid will also fall under the new rules. 

A number of republican governors, who have long fought mask mandates and other safety regulations intended to stop the spread of the deadly virus, immediately argued that this rule change infringed on their personal freedom and was unconstitutional. The change was an attack on private businesses and states rights, they claimed. 

“Biden’s vaccine mandate is an assault on private businesses,” tweeted Texas Governor Greg Abbott. “I issued an Executive Order protecting Texans’ right to choose whether they get the COVID vaccine & added it to the special session agenda. Texas is already working to halt this power grab.” Last week Abbott enacted legislation that would prevent the majority of women in Texas from choosing whether or not to receive an abortion, even in cases of rape and incest. 

Texas Attorney General Ken Paxton also questioned Biden’s ability to issue the mandates. “I don’t believe he has the authority to just dictate again from the presidency that every worker in America that works for a large company or a small company has to get a vaccine,” he said on a radio program hosted by former President Donald Trump advisor Steve Bannon. “That is outside the role of the president to dictate.”

Governor Kristi Noem of South Dakota wrote on Twitter that she would see Biden “in court,” and Governor Henry McMaster of South Carolina said in a statement that “Biden and the radical Democrats (have) thumbed their noses at the Constitution.” Governor Mark Gordon of Wyoming also said he was preparing his state’s attorney general to take action. 

In a fundraising email sent Friday, Florida Governor Ron DeSantis of Florida wrote, “Joe Biden has declared war on constitutional government, the rule of law, and the jobs and livelihoods of millions of Americans.”

Biden appeared prepared for these attacks, and confident in the constitutional basis of his actions. “If those governors won’t help us beat the pandemic, I will use my power as president to get them out of the way,” he said during his announcement on Thursday. 

On Friday he delivered a stronger message to his opposition. “Have at it,” he said. “I am so disappointed, particularly that some of the Republican governors have been so cavalier with the health of these kids, so cavalier with the health of their communities.”

Biden’s regulations would be enforced through the Department of Labor’s Occupational Safety and Health Administration (OSHA), the agency responsible for overseeing the safety of laborers in the United States. The group has previously issued emergency guidance including requirements for personal protective equipment during the pandemic. 

OSHA will enforce the rule, which Biden said wouldn’t take effect for weeks, by collecting violation reports and sending inspectors. They will issue fines ranging from $13,600 to $136,000 to firms who violate the law. 

A 1970 law gives the federal government the authority to protect employees from “grave dangers” in the workplace, but the law has never before been used to require a vaccine. 

Still, Republicans believe they can fight the rule in court. “Federal government mandates, of dubious legality, will further alienate the skeptical, undermine our institutions, and punish ordinary business owners and their employees,” Senator Patrick J. Toomey (R-PA) said Friday.

The White House stood by its ruling, assuring the public that it stood on strong legal ground. “This action is both clearly legal and needed to help save lives and stop the spread of COVID-19,” wrote representatives in a statement. 

Any legal action would likely be around whether or not the emergence of the Delta variant creates a “grave danger” to workers. The U.S. has seen a 300% surge in daily COVID-19 infections, nearly 250% more hospitalizations and about 200% more deaths compared to this time last year. The vast majority of severe illness and death from the virus are occurring amongst Americans who have not yet received the full vaccination. 

“We’ve been patient. But our patience is wearing thin, and your refusal has cost all of us,” said Biden on Thursday.  Unvaccinated Americans “can cause a lot of damage, and they are.”