Tucker Carlson took on the idea that the ACLU should "rethink free speech" following the Charlottesville white supremacist riots. 

In a New York Times op-ed, attorney K-Sue Park wrote that the ACLU should reconsider its long-held positions on free speech and potentially refuse to defend the First Amendment rights of neo-Nazi groups. 

Tucker on ESPN's Robert Lee Move: The 'Hysterical, Reactionary & Stupid' Left 

ISIS Video Uses 10-Year-Old American Boy to Spread Propaganda

"Sometimes standing on the wrong side of history in defense of a cause you think is right is still just standing on the wrong side of history," Park argued. 

Carlson said going back a century, the ACLU has always defended the most offensive types of speech on the grounds that "if free speech doesn't protect unpopular speech, it's not really free."

But now, he said the group appears to be "caving to mob pressure" by choosing not to defend white supremacist groups if they carry firearms - even legal ones - during a protest. 

He debated the issue with LawNewz.com editor and attorney Elura Nanos, who agreed with the ACLU not devoting its "limited resources" to neo-Nazi groups.

She said no law has changed, but now these hate groups are becoming more violent and growing because they're being "emboldened" by President Trump.

Carlson called that "totally absurd," arguing that on the left, people are increasingly declaring that "speech equals violence [and] I'm not going to defend that."

Watch the full back-and-forth above.

Steyn on Hillary Calling Trump a 'Creep': 'I Thought She Was Recalling Her 1st Date With Bill'

WATCH: Tucker Responds After 'Humorless' Media Jumps on Him for Trump-Eclipse Joke

Tucker Calls Out the Left's 'Systematic Suppression' of Speech They Disagree With