Jenny Racicot, who accused Graham Platner of sexual assault in an interview published in Politico on Monday, detailed her recollection of the alleged attack in an extended interview with the CNN host Jake Tapper that aired on Monday evening.

She said that Mr. Platner had drunkenly assaulted her at her home in 2021, and she described the encounter as rape. Detailing the violent struggle that she said took place, she recounted that a sewing cabinet had been knocked over, causing a needle to be stuck in her leg.

“This is something that I tried for many years to forget,” Ms. Racicot said.

Mr. Platner, 41, called all allegations of nonconsensual behavior “categorically false” in a video posted on social media on Monday.

Ms. Racicot, 41, said that she met Mr. Platner on a dating app in 2019 and found him “intelligent” and “charming,” but that he also self-medicated with alcohol. On one night in 2021, he texted her that he would come over to her house, she said.

“I said, ‘No, don’t come over,’” Ms. Racicot told CNN. “Like, ‘I’m not in the mood. Don’t come over.’” She didn’t hear back from him, so she assumed “he got the message,” she said, but “half an hour later, I heard a noise outside my door and then he came in. He just came into my house. It was unlocked.”

After entering her home uninvited, Mr. Platner “jumped on top of” her while she was lying on the couch and “indicated that he had intentions that were sexual in nature,” Ms. Racicot said.

“I remember just at first being like, ‘Hey, I’m not into this,’” she said. “‘Like, don’t, I’m not in the mood.’” Then she noticed a “look in his eyes” and the smell of alcohol, she said.

“I was like, ‘This is different — he is heavily intoxicated,’” she said. “And that blank stare was kind of like a photographic memory that I still have of that night.”

Ms. Racicot said that she pushed Mr. Platner away when he was on top of her that night in 2021, and that he backed into her antique sewing kit, causing sewing needles, tape and yarn to scatter and fall to the floor.

“I remember specifically him grabbing at my chest, and I hit his hand and I said, ‘Don’t touch me,’” she said.

Evaluating the situation and his level of intoxication, “I basically felt safest just complying,” Ms. Racicot said. Before that point, she maintained that she had so stridently said no that, in her view, he could not have believed she was consenting.

“I don’t believe that you can think that that scenario was consensual,” she said, adding, “when somebody in the middle of it says, ‘Don’t touch me,’ like, that’s obviously not consensual,” she said, adding that he had apologized in moments of lucidity.

At the same time, she said, he seemed unaware of what he had done. He fell asleep in her bed afterward, she said, and then woke up and “went to go put his arm around” her, which Ms. Racicot said made her realize “this person doesn’t know that what happened wasn’t OK.”

“I remember taking his arm and throwing it back at him, and I said, ‘Are you serious, Graham?’” she recounted, adding an expletive. “And he’s like, ‘What?’ And I’m like, ‘Do you not remember what happened last night?’ He was like, ‘No.’”

She had lain in bed “in a state of panic” all night, she said, and later worried that he had gotten her pregnant. She said he did not speak to her again.

Ms. Racicot had described some of what happened that night to The New York Times this spring, saying that he had arrived at her house drunk after she had asked him not to come over. At the time, she declined to share further details of the encounter on the record, but she said she had found his behavior “reckless” and “unsettling” and had cut off contact with him soon after that episode.

She said on CNN that at the time she “felt really protective of my own privacy.” But after the article came out and she was named in it, she said, “I kind of just made the decision that I’m going to say my piece and get it out there.”

Ms. Racicot also said she had hesitated to speak out against Mr. Platner because she “felt really uncomfortable with the responsibility of and the weight of my story and what that might do,” given that she agrees with his politics.

“I understand why people want someone like him in office, and I felt like me coming forward would essentially potentially take that away,” she said.

She declined to say whether or not Maine voters should cast their ballots for Mr. Platner when asked by Mr. Tapper.

“I’m just here to tell my story, to give a clearer picture of who he is and the type of past that he has,” she said. “I just think it’s fair to the democratic process to let people know who they’re voting for.”