Manhattan Institute senior fellow Christopher Rufo once again took aim at MSNBC host Joy Reid over her claim that critical race theory (CRT) was not being taught in schools following the decision by the National Education Association (NEA) to promote the teaching of the controversial ideology. 

Rufo, a leading critic of CRT, ripped the left-wing host Monday on both social media and in an op-ed for the New York Post, pointing out that the move by the largest teachers union in the nation contradicted Reid's earlier claim that the ideology was only something taught in law schools. 

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"Joy Reid: Critical race theory is only taught in law schools. NEA: Actually, critical race theory is our #1 priority and we want to implement it in all 50 states and 14,000 local school districts," Rufo wrote in a tweet, pointing out the discrepancy in what Reid was claiming versus the NEA's decision.

"Progressives such as MSNBC host Joy Reid can no longer disingenuously claim that critical race theory is only taught in law schools or that it is only a 'lens' for examining American history," he wrote in the op-ed. "The teachers union has nationalized critical race theory and committed to the full range of left-wing radicalism, including opposition to 'capitalism' and 'anthropocentrism.'

In a weekend decision, the NEA approved a plan to "publicize" CRT and provide resources to fight back against those speaking out against it. The union went so far as to call the divisive ideology "reasonable and appropriate" for young students. 

CRITICAL RACE THEORY OPPONENTS TO BE TARGETED, ‘RESEARCHED' BY NEA TEACHERS' UNION

The sudden move by the union contradicted previous left-wing talking points, including Reid's claims, that CRT was not being taught to children in schools because it was too complex for students in the the K-12 age range. 

Reid previously made her claim about the teaching of CRT on June 23, during what was supposed to be a debate between Rufo and herself on MSNBC over the ideology, but quickly devolved into her constantly interrupting him and not allowing him to speak. 

Rufo subsequently spoke with Fox News after attempting to debate Reid, and said his research proved the ideology was being taught "widely" in schools. He said the media was scared of his message because it was the truth and it was working to let people know the dangers of teaching the subject.

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"I think the political left and its enablers in the media are scared of my message because it's the truth and because it's working. Critical race theory, as I've documented in more than a dozen original reports, is being taught widely in American public schools," he told Fox. "And they want to just deny that it's even happening, despite evidence from students, from parents, from teachers, despite now hundreds of different reports from around the country. They know that this is politically toxic. They know that it's intellectually bankrupt, and they just want to hide the truth."

Fox News' Brian Flood and Michael Ruiz contributed to this report.