The co-founder of the Black Lives Matter movement claimed Monday on MSNBC that hate speech is not protected under the U.S. Constitution.

Host Katy Tur asked Dignity and Power Now founder Patrisse Cullors about President Donald Trump's initial statement on the violence from white supremacists at a Charlottesville, Va. rally, which appeared to equate the neo-Nazis with the counter-protesters.

"Draw a distinction for me, if you will," Tur asked Cullors, who first spread the hashtag #BlackLivesMatter.

"I think what is important at this moment is white nationalists are actually fighting to take away people's rights," she responded. "Black Lives Matter and groups like Black Lives Matter are fighting for equality."

"Hate speech, which is what we're seeing coming out of white nationalists groups, is not protected under the First Amendment rights," she continued.

Cullors is incorrect. Under existing Supreme Court precedent, the U.S. government cannot sanction or ban speech simply because it is hateful or unpopular.

That principle was most recently upheld in June in the case of Matal v. Tam, when the Supreme Court ruled unanimously that the government cannot deny trademarks to brand names it finds offensive.

Justice Samuel Alito's majority opinion argued that the banning of hateful speech "strikes at the heart of the First Amendment. Speech that demeans on the basis of race, ethnicity, gender, religion, age, disability, or any other similar ground is hateful; but the proudest boast of our free speech jurisprudence is that we protect the freedom to express ‘the thought that we hate.'"