Taking his toughest tone yet against those Americans still unvaccinated, President Joe Biden has triggered vows of legal challenges from GOP governors representing some of the very states where he's trying to use mandates to get more people inoculated.
At least 19 Republican governors have lashed back at Biden's promise to use OSHA to pressure employers with more than 100 employees to mandate COVID-19 vaccines or have workers submit to weekly testing. The Republican governors called the mandate an overreach that will force Americans to choose between their job and the vaccine.
While Biden said on Friday morning, during a visit to local middle school, that all scientists would agree with his new strategy -- that using protecting public health as a justification for mandates makes "considerable sense," his taking a combative tone may come with new political and public health risks and further polarize Americans, fueling the already bitter political divide around the pandemic.
South Dakota GOP Gov. Kristi Noem, a potential 2024 presidential candidate, tweeted to Biden, "see you in court," while Mississippi GOP Gov. Tate Reeves compared him to a "tyrant," and South Carolina GOP Gov. Henry McMaster said he'll "fight them to the gates of hell" to stop the move. House Minority Leader Kevin McCarthy called Biden's approach "flat-out un-American."
When ABC News Congressional Correspondent Rachel Scott asked Biden on Friday what his message was to Republicans threatening to challenge his move in court, he responded, "Have at it."
He continued, "Look, I am so disappointed that particularly some Republican governors have been so cavalier with the health of these kids, so cavalier with the health of their communities. We're playing for real here -- this isn't a game."
While Biden has previously said he wouldn't impose vaccine mandates, he said Friday that vaccine requirements are "nothing new." However, past vaccines requirements for measles, mumps and rubella, for instance, have historically been implemented at a state and local level -- and at times when the country wasn't already so divided politically
In his address to the nation on Thursday introducing his new six-part approach, a frustrated Biden went after the unvaccinated and elected officials for standing in the way of public health measures and, he said, causing people to die.
"These pandemic politics, as I refer to it, are making people sick, causing unvaccinated people to die. We cannot allow these actions to stand in the way of the large majority of Americans who have done their part and want to get back to life as normal," Biden said.
"My message to unvaccinated Americans is this: What more is there to wait for? What more do you need to see?" he said. "We've been patient, but our patience is wearing thin. And your refusal has cost all of us."
He called out the governors, many of whom are now criticizing his approach, saying, "if these governors won't help us beat the pandemic, I'll use my power as president to get them out of the way."
He added, "Let me be blunt. My plan also takes on elected officials in states that are undermining you and these life-saving actions. Right now, local school officials are trying to keep children safe in a pandemic while their governor picks a fight with them and even threatens their salaries or their jobs," he said. He promised his administration would to pay back salaries withheld from those opposing mask bans.
White House press secretary Jen Psaki was asked on Friday what caused Biden and the rest of the administration to change its tune on blaming the unvaccinated for the pandemic -- after Psaki said in June that she didn’t want to place blame.
She said Biden on Thursday was "channeling the frustration" of millions who are vaccinated as the pandemic rages, while pointing a finger at Republicans.
"We didn't anticipate, I will say, that when there was a vaccine approved under a Republican president, that the Republican president took, that there would be such hesitation, opposition vehement opposition in some cases from so many people of his own party in this country," she said.
While 75% of adults have gotten a shot, per data from the Centers for Disease Control and Prevention, vaccinations have stalled in recent months despite widespread availability as the hospitals across the country face another surge of the virus timed with the start of a new school year.
Biden's new approach to getting more shots into arms comes as his approval for handling the pandemic has dropped sharply from 62% in June to 52% now.
The latest ABC News/Washington Post poll found also that vaccine hesitancy has subsided in the face of the delta surge, with the share of Americans who are disinclined to get a coronavirus shot now just half what it was last January. Among those unvaccinated adults, about 7 in 10 are skeptical of the vaccines' safety and effectiveness, 9 in 10 see vaccination as a personal choice rather than a broader responsibility and just 16% have been encouraged by someone close to them to get a shot.
It's unclear if Biden will break through to that group.
A White House spokesman declined to say whether public polling on why certain people remain unvaccinated informed the decision to institute these new requirements, or otherwise explain how Americans' attitudes toward COVID-19 vaccines impacted the president's decision.
The spokesman said the decision to enact the new requirements was "not rooted in any political focus, rather on what's going to work."
As some GOP governors say they're preparing lawsuits, White House COVID-19 Response Coordinator Jeff Zients in defending the mandates on Friday argued that COVID-19 is a "public health issue, not a political issue."
"We know that vaccination requirements work," Zients said, pointing to "significant increases in vaccination rates at companies, health care systems, universities, that implement vaccine requirements."
As Biden did on Thursday, Zients pointed specifically to companies like Fox News -- which has provided a platform for vaccine misinformation and has repeatedly railed against Biden's COVID-19 response -- but which is also participating in a version of a vaccination reporting requirement itself.
"The president's actions will accelerate that number of companies across the board for employers over a hundred, and that includes Fox News, which already has that vaccination requirement in place to keep its own employees safe."
ABC News' Ben Gittleson and Sasha Peznik contributed to this report.