What critical race theory is -- and isn't

(CNN)Critical race theory. You may be hearing those three words a lot these days.

Lawmakers in Tennessee and Idaho have banned its teaching from their public schools' curriculum, while parents in Texas are opposing a school district's efforts to combat racism with lessons in "cultural awareness" -- seen by some as critical race theory.
It's a concept that's been around for decades and that seeks to understand and address inequality and racism in the US. The term also has become politicized and been attacked by its critics as a Marxist ideology that's a threat to the American way of life.
To get a deeper understanding of what critical race theory is -- and isn't -- we talked to one of the scholars behind it.

What's critical race theory?

Critical race theory recognizes that systemic racism is part of American society and challenges the beliefs that allow it to flourish.
"Critical race theory is a practice. It's an approach to grappling with a history of White supremacy that rejects the belief that what's in the past is in the past, and that the laws and systems that grow from that past are detached from it," said Kimberlé Crenshaw, a founding critical race theorist and a law professor who teaches at UCLA and Columbia University.
A young boy drinks from the "colored" water fountain on the county courthouse lawn in Halifax, North Carolina, in 1938.
Critical race theorists believe that racism is an everyday experience for most people of color, and that a large part of society has no interest in doing away with it because it benefits White elites.
Many also believe that American institutions are racist and that people are privileged or oppressed because of their race.
While the theory was started as a way to examine how laws and systems promote inequality, it has since expanded.
"Critical race theory attends not only to law's transformative role which is often celebrated, but also to its role in establishing the very rights and privileges that legal reform was set to dismantle," Crenshaw told CNN.
"Like American history itself, a proper understanding of the ground upon which we stand requires a balanced assessment, not a simplistic commitment to jingoistic accounts of our nation's past and current dynamics."

Who came up with the idea?

Crenshaw is one of its founding scholars and hosted a workshop on the critical race theory movement in 1989. But the idea behind it goes back much further, to the work of civil rights activists such as W.E.B. Du Bois, Fannie Lou Hamer and Pauli Murray.
"Everything builds on what came before," Crenshaw said, adding that "the so-called American dilemma was not simply a matter of prejudice but a matter of structured disadvantages that stretched across American society."
Crenshaw said she and others "took up the task of exploring the role that law played in establishing the very practices of exclusion and disadvantage."
"Words That Wound: Critical Race Theory, Assaultive Speech, And The First Amendment," a book by several legal scholars.
Some of the theory's earliest origins can be traced back to the 1970s, when lawyers, activists and legal scholars realized the advances of the civil rights era of the 1960s had stalled, according to the book, "Critical Race Theory: An Introduction."
Crenshaw was among a group of intellectuals, along with Derrick Bell, Alan Freeman and Richard Delgado, who attended a 1989 conference in Wisc