Senior advisor for former New York City Mayor Mike Bloomberg’s presidential campaign criticized Vermont Sen. Bernie Sanders on Tuesday over past comments regarding children’s genitalia.

Tim O’Brien spoke on CNN’s “New Day” about Sanders, who is currently leading the pack in the presidential race. CNN anchor Alisyn Camerota asked O’Brien how Bloomberg’s campaign can avoid being the target among other Democratic candidates, noting that the former mayor plans to challenge Sanders at Tuesday’s debate.

O’Brien then began to describe what he sees as the “loony side of Bernie,” pointing out an essay written by the Vermont senator in the 1970s about children going around naked and being “liable to see each others sexual organs.”

“We have a candidate who has risen in the polls because of this track record,” O’Brien said about Sanders. “Bernie has loopy stuff in his background, saying women get cancer from having too many orgasms or toddlers should run around naked and touch each other’s genitals to insulate themselves from porn?”

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“What?!” replied Camerota, appearing shocked at the comments.

Sanders’ 1970s essay spoke about the pornography business and how the economy “makes its money by playing on people’s sexual frustrations.” (RELATED: ‘I Was Wrong’: MSNBC’s Chris Matthews Issues On-Air Apology To Sanders After Comparing Success To Rise Of Nazi Germany)

“Now, if children go around naked, they are liable to see each others sexual organs, and maybe even touch them,” Sanders wrote in the essay. “Terrible thing! If we [raise] children up like this it will probably ruin the whole pornography business, not to mention the large segment of the general economy which makes its money by playing on people’s sexual frustrations.”

O’Brien continued on, expressing his wonder over how this side of Sanders has remained largely untouched.

“He has written about women’s rape fantasies, that hasn’t been surfaced,” O’Brien continued.