Don Lemon found himself in hot water for claiming Republican presidential hopeful Nikki Haley was past her "prime," but the CNN host has a long history of controversial rhetoric. 

 "Nikki Haley isn't in her prime, sorry. A woman is considered to be in their prime in 20s and 30s and maybe 40s," Lemon said during "CNN This Morning" on Thursday. 

Lemon's co-host Poppy Harlow – who appeared stunned -- questioned his claim and asked him to explain what he meant by Haley, who is 51, not being in her prime. Lemon noted that he googled it. 

"It depends, just like prime, if you look it up. If you Google it, when is a woman in her prime, it'll say 20s, 30s and 40s," Lemon continued. "I’m not saying I agree with that. I think she has to be careful about saying that, you know, politicians are in their prime."

DON LEMON'S CNN COLLEAGUES ANGERED BY ‘STUPID’ REMARKS ABOUT NIKKI HALEY BEING PAST HER PRIME

Don Lemon

Don Lemon has a long history of controversial rhetoric.  (CNN screenshot)

The comments sparked widespread backlash and Lemon has since apologized, although the mea culpa sparked even more tension inside CNN. 

It wasn’t the first time Lemon generated negative headlines with controversial rhetoric. Here are some of his noteworthy gaffes: 

Lemon asks Bill Cosby accuser why she didn’t bite his penis to prevent rape

In 2014, Lemon interviewed Joan Tarshis, who had recently accused Bill Cosby of forcing her to perform oral sex decades prior. Lemon informed Tarshis that "there are ways not to perform oral sex if you didn't want to do it," before elaborating.

"Meaning the using of the teeth, right? Biting," Lemon said.

Lemon eventually apologized after widespread backlash. 

CNN'S DON LEMON ROASTED AS ‘SEXIST’ FOR SAYING NIKKI HALEY IS PAST HER ‘PRIME’

Lemon defends men's sports earning more money

Lemon got into a heated exchange with his CNN co-anchors in December after observing that male athletes earn more money than female athletes because men’s sports earn more money than women’s sports.

Lemon made his comments during a "CNN This Morning" segment on the pay gap between the U.S. men’s and U.S. women’s national soccer teams, frustrating his co-anchors Kaitlin Collins and Poppy Harlow, who argued that male athletes earn more because the media gives men's sports a bigger platform.

Insisting, "I’m not a sexist," Lemon gave the counterargument that our "capitalist society" benefits products that are in higher demand, in this case men’s sports, thus male athletes receive higher earnings.

Lemon said, "I know everyone’s gonna hate me, but the men’s team makes more money. If they make more money, then they should get more money." The two female co-anchors immediately bristled at his remark and tried to interrupt him.

Before being completely talked over, he added, "The men’s team makes more money because people are more interested in the men!"

Lemon asks female colleague if she has "mommy brain"

Lemon came under fire in September when he asked CNN analyst S.E. Cupp if she was suffering from "mommy brain."

Lemon and Cupp were discussing classified documents seized at the home of former President Trump when Cupp appeared to briefly lose her thought.  

"Did you lose your train of thought? I do it all the time," Lemon said. "Is it mommy brain?" ‘

Cupp appeared annoyed by the comment and responded, "No, Don, I just forgot what I was going to say."

Lemon then insisted, "We’re not beating up on you, we’re just having fun."

Lemon compares Trump supporters to Ku Klux Klan members, Nazis

In 2021, Lemon said Trump supporters were tarred by their association with objectionable people who backed his candidacy, including Ku Klux Klan members, during a conversation about the Jan. 6 Capitol riot. 

"If you are on that side, you need to think about the side you're on," Lemon said. "I am never on the side of the Klan. Principled people, conservative or liberal, never on the Klan side. Principled people, conservative or liberal, never on the Nazi side. Principled people who are conservative or liberal, never on the side that treats their fellow Americans as less than, that says your fellow Americans should not exist ... that sides with slavery."

Lemon then said, "If you voted for Trump, you voted for the person who the Klan supported. You voted for the person who Nazis support." 

DON LEMON PRAISED WH HOPEFULS CLINTON, HARRIS, WARREN, KLOBUCHAR, ALL OLDER THAN NIKKI HALEY WHEN THEY RAN

Kaitlan Collins, Don Lemon, Poppy Harlow on red carpet

CNN CEO Chris Licht called Don Lemon’s recent comments "upsetting, unacceptable and unfair" to his morning show co-hosts Poppy Harlow and Kaitlan Collins. (Mike Coppola/Getty Images for CNN)

Lemon defends Antifa

Lemon defended the radical far-left group Antifa on the heels of violent protests throughout the nation in 2018. The extremist group often engages in violence against those it deems far-right enemies.

"It says it right in the name: Antifa, anti-fascism, which was what they were there fighting," Lemon said of one incident involving it and neo-Nazis. "Listen, no organization is perfect. There was some violence. No one condones violence… but there were different reasons for Antifa and for these neo-Nazis to be there. One, racists, fascists, the other group, fighting racist fascists. There is a distinction there."

Lemon erupts on unvaccinated people going to hospitals

Lemon fumed last year over people not vaccinated against coronavirus "taking up the space" in hospitals from vaccinated people who are "playing by the rules," suggesting they should not go to the hospital if they get sick in the fall of 2021. 

Lemon, responding to a story about a man whose cancer-stricken wife was released from the hospital early because of a lack of beds and died, predicted the future was going to be between the vaccinated and unvaccinated people across the country. He then blamed "selfish" unvaccinated people putting stress and strain on the system.

"If you’re not going to get vaccinated, you don’t want to social distance, you don’t want to wear a mask, then maybe you don’t want to go to the hospital when you get sick," Lemon said, visibly frustrated. "I know that sounds harsh, but you’re taking up the space for people who are doing things the right way."

Lemon says Obama ‘better looking,’ ‘smarter’ and has ‘more accomplished’ wife than Trump

In 2020, Lemon accused then-President Trump of letting former President Obama get under his skin because he is "better looking," better educated" and has a "more accomplished" wife, in a segment that quickly went viral. 

"What is it about President Obama that really gets under your skin? Is it because he’s smarter than you? Better educated? Made it on his own? Didn’t need daddy’s help? Wife is more accomplished? Better looking? I don’t know, what is it? What is it about him? That he’s a black man that’s accomplished being president? That he punked you on the whole birth certificate thing? What is it about him? Just wondering," Lemon said slowly.

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Lemon invokes Hitler while discussing Trump

Lemon compared Trump and Adolf Hitler in 2019 while arguing that such "bad people" shouldn't be given a platform, but backed down after widespread backlash.  

During their hand-off, Lemon’s ex-primetime colleague Chris Cuomo began by describing 2020 as the most "definitional" election in his lifetime. Lemon urged Cuomo, who has since been fired, to "think about the most despicable people in history" and warned him that he was going to use an "extreme example."

"Think about Hitler. Think about any of those people... if you could look back in history, would you say, 'Well, I'm so glad that person was allowed a platform so that they could spread their hate and propaganda and lies,' or would you say, 'That probably wasn't the right thing to do to spread that because you knew in that moment that was a bad person, and they were doing bad things," Lemon said. 

Cuomo called the example "extreme" but Lemon initially doubled down. 

"Listen, for people like me, how this president feels about the Central Park Five, that could be a life-or-death issue for people like me," Lemon shot back. "He took a big part of their life away... and demonizing immigrants and talking about 'sh--hole countries' and saying that 'there were very fine people on both sides.' For people of color in this country, it is a life or death issue... so I'm just saying we just need to be careful about having 'these are standard rules.' This is not standard. This is not normal."

After additional pushback from Cuomo, Lemon declared he wasn’t making an apples-to-apples comparison. 

"I'm comparing the way you would cover someone who is a bad person who does bad things," he said.  

Lemon apologized later in the week after CNN came under fire for the comments. 

"I didn’t mean to compare Hitler to the president, but it was inartful," Lemon said.

Fox News’ Gabriel Hays, Hanna Panreck and Joseph A. Wulfsohn contributed to this report. 

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