Some lawmakers want to ban critical race theory in schools. So, what is it?

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Last week, the Florida State Board of Education approved a rule to ban lessons on critical race theory in its public schools. Since January, Republicans in at least 22 states — including Maine, New Hampshire, and Rhode Island — have proposed comparable legislation.

The measures are an outgrowth of similar efforts by Donald Trump, and are part of the broader conservative backlash to the national reckoning on race that occurred after Minneapolis police murdered George Floyd in May 2020.

Now, as national debate over race-related curriculums rages on, here is an explainer on the subject and the controversy surrounding it.

What exactly is critical race theory?

Rather than a single concept, critical race theory refers to an intellectual movement founded by legal scholars of color in the 1970s and 1980s. It is premised on the belief that race is a social reality, not a biological one, and that racism continues to be a pervasive part of our society despite substantial gains in civil rights over past decades.

For critical race theorists, racism is not limited to isolated incidents of individual prejudice. Rather, racism is embedded in the very structure of the United States and its foundational institutions, like the law and the government.

Other distinctive features of critical race theory include its recognition of the interconnectedness of various social identities, such as race, gender, sexuality, and class — and its emphasis on the lived experiences of people of color.

But the “heart” of critical race theory “is to shed light on the unfair and inequitable ways that racial power has been woven into the fabric of our institutions,” said Kendall Thomas, a professor at Columbia Law School who coedited the book “Critical Race Theory: The Key Writings That Formed the Movement.”

What the critics say

One objection often levied against critical race theory is that its focus on racism within civic institutions is unpatriotic and anti-American.

Before the vote on the issue in Florida, Governor Ron DeSantis said critical race theory teaches children that “the country is rotten and that our institutions are illegitimate.”

Other detractors say the theory is divisive and even racist, since they believe its framework vilifies white people and victimizes people of color.

Arkansas, Idaho, Iowa, Oklahoma, and Texas also have recently adopted bans on teaching critical race theory and related concepts in their public schools or state agencies.

“Now more than ever, we need policies that bring us together, not rip us apart,” Oklahoma Governor Kevin Stitt said in a video on Twitter after he signed the law prohibiting schools from teaching critical race theory. “As governor, I firmly believe that not one cent of taxpayer money should be used to define and divide young Oklahomans about their race or sex.”

But scholars who study critical race theory counter that the framework isn’t actually about division or blame — and efforts to portray it as such are in bad faith.

Under critical race theory, “the problem of racism is a social problem,” Thomas said. “Therefore, it’s an approach that’s not interested in assigning individual blame or guilt, or telling stories about animus or hatred.”

Khiara Bridges, a professor at UC Berkeley School of Law and the author of “Critical Race Theory: A Primer,” said bans on critical race theory in public schools are an “intentional misrepresentation” of the issue, since it is by definition a legal framework.

“For critical race theory to be taught in K-12 schools, kindergarteners through 12th-graders would have to have some knowledge of the law,” she said. “They’d have to have a sizable amount of legal theory under their belt.”

The view from New England

Of the attempts in New England states, the push to ban critical race theory has gained the most traction in New Hampshire.

On June 3, New Hampshire’s Senate passed its $13 billion budget that included a ban on teaching “divisive concepts” — such as the notion that any individual is inherently racist or sexist. New Hampshire Governor Chris Sununu, a Republican, has said he would veto the measure.

In Rhode Island, a similar bill to “prohibit the teaching of divisive concepts” is pending review from the House Education Committee. In Maine, a measure to ban public school teachers from “engaging in political ideological or religious advocacy” was recently referred to the Committee on Education and Cultural Affairs.

The issue has generated little buzz among Massachusetts lawmakers.

Bridges questioned why the GOP has chosen the present moment to attack critical race theory, despite the fact that it was formulated more than four decades ago.

“I think it’s about sparking a culture war, sparking racial division, and delegitimizing whatever sort of movements we saw around racial justice,” she said, referring to widespread protests in 2020 in support of Black Lives Matter.

Thomas said he anticipates lawsuits will challenge the bans on critical race theory, since he believes they are a “clear and incontrovertible” violation of the right to free speech.

“I would hope that the courts will exercise their responsibility to block this attempt to inflict a body blow on the First Amendment,” he said.

Camille Caldera was a Globe intern in 2022.Follow her on Twitter @camille_caldera.