(CNN) -- Supreme Court Justice Clarence Thomas was a binge drinker who had a pornography habit or fetish in the 1980s, then changed radically when he stopped drinking alcohol, his former girlfriend told CNN on Monday.

Lillian McEwen, who dated Thomas for several years before he was nominated to the Supreme Court in 1991, provided CNN's "Larry King Live" program with a harsh depiction of Thomas. She said when they first met, he might have been a "raving alcoholic" who used pornography to help fulfill sexual fantasies, but then gave up drinking and transformed into an angry, obsessive man who bullied his son.

King said during the program that Thomas' office declined offers to comment on the topics of the interview.

Thomas almost had his Supreme Court nomination derailed when another woman, Anita Hill, accused him of sexual harassment when they worked together in the 1980s at the U.S. Department of Education and then the Equal Employment Opportunity Commission.

During his Senate confirmation hearing, Thomas angrily denied any improper behavior involving Hill, calling the allegations a form of lynching.

McEwen, a former prosecutor and administrative law judge who has written her own memoir and is seeking a publisher, said she believed Hill's account of sexually suggestive statements by Thomas because of his use of pornography.

"I suppose I would call it a fetish or a hobby," she said of Thomas. "It was something that was very important to him, something that he talked about."

She said the pornography bored her and she wouldn't watch pornographic videos with him, but she also said she enabled his fantasies tied to the pornography "because we had a sexual relationship."

"I didn't disapprove of it. I just didn't care," McEwen said.

According to McEwen, Thomas underwent a major personality change when he gave up alcohol that eventually caused her to leave the relationship.

"Clarence became not the person I knew when I first met him," she said, adding that he "drank to excess" when they first met and might have been a "raving alcoholic" at that time. When he gave up alcohol, she said, he became "angry, short-tempered, asexual" and obsessive with ambition and what she called "weird things," such as long runs in the dark before dawn.

Asked if she believed back then he was qualified to reach his goal of being a Supreme Court justice, McEwen said it was a difficult question and cited "instability," a "lack of intellectual curiosity," and trouble with concentrating when reading for a long time as issues about Thomas that would make it difficult to do the job.

Thomas"went backwards" during the time she knew him and became a bully to his son, McEwen said, and she added that she once turned him down when Thomas asked if he and his son could move in with her.

Eventually, McEwen said, "it was time for me to go."

Thomas is one of the most conservative justices on the nine-member Supreme Court, and is known for rarely if ever asking questions during hearings.

To McEwen, his conservative rulings amount to a kind of revenge fueled by anger against liberals who he believes turned against him.

"His enemies are people who are active in civil rights, professors who have criticized him and anybody who disagrees with the conservative friends that he has such as Rush Limbaugh," she said.

McEwen had never spoken publicly about her relationship with Thomas until the recent revelation that Thomas' wife, conservative activist Virginia Thomas, left a voicemail for Anita Hill asking her to apologize for her 1991 testimony at the confirmation hearing.

According to McEwen, she was "tricked" by a Washington Post reporter into commenting on the Virginia Thomas phone call to Hill and decided is was time to come forward with her story.

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