What is the controversy surrounding Critical Race Theory in a nutshell?

What is the controversy surrounding Critical Race Theory in a nutshell? How does cultural competence or culturally relevant teaching help close the achievement gap? What are the major organizations that provide teachers materials, lessons and background information for teaching diversity, tolerance, and cultural competency? What was the most interesting thing you learned? Make a connection and raise a question.
https://www.kqed.org/education/535060/how-can-students-fight-racism-in-schools

https://www.csba.org/-/media/CSBA/Files/GovernanceResources/EducationalEquity/CriticalRaceTheory_FAQ_7-1-2021.ashx?la=en&rev=43cc698d0964446e889fd1a45ff136a9
https://www.learningforjustice.org/magazine/when-educators-understand-race-and-racism