Chris Clevenger, the spokesman for the campaign, told WSAZ.com said he called O'Neill and stepped down after seeing the controversial post where O'Neill claims to have been "sexually intimate" with more than 50 "very attractive" women.
After posting the message Friday, he edited it to remove some identifying information about the women.
The Columbus Dispatch reports the Supreme Court justice confirmed he wrote the post and said, "I'm a candidate for governor and I assume I'm the next target".
"So I figure let's just get it out here on Front Street right here and now", he added, referring to the street where the Supreme Court building sits.
He was elected to the Ohio Supreme Court in 2012 and began serving in 2013. No words can convey my shock. "This gross disrespect for women shakes the public's confidence in the integrity of the judiciary".
O'Neill, a Democrat, says he is running for OH governor. In October, he announced his run for Ohio governor but said he would hold his seat on the Ohio Supreme Court until he officially submits his petitions for candidacy.
Many viewed the post as remarkably tone-deaf in the national debate over sexual misconduct allegations and evidence against a series of powerful men in Hollywood, the media and in politics. As a victim of sexual assault, I can not in good faith remain a part of #TeamONeill.
Only a day earlier, Ms Sutton unveiled a plan to combat sexual harassment and sexual assault in state government, where two lawmakers have recently resigned amid sexual misconduct allegations.
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Roughly six hours after his initial post, O'Neill hid or deleted it from his Facebook page.
The post drew thousands of comments, reactions and shares on Facebook and was a trending topic on Twitter, drawing mostly negative reaction but some positive comments.
'Now that the dogs of war are calling for the head of Senator Al Franken I believe it is time to speak up on behalf of all heterosexual males, ' O'Neil wrote. Al Franken, who is accused of groping a woman during a USO trip in 2006.
"The media is about to determine the election of a United States Senate Campaign".
Critics say O'Neill is trivializing the issue.
Well, that's one way to handle any stories that could come out about you.
It was during this candidacy that he made a decision to announce his sexual exploits, because he was "so disappointed by this national feeding frenzy about sexual indiscretions decades ago", referring to Democratic Senator Al Franken of Minnesota, who has been recently accused of forcibly kissing and groping a radio news anchor a decade ago.