Donald J. Trump was emphatic in the second presidential debate: Yes, he had boasted about kissing women without permission and grabbing their genitals. But he had never actually done those things, he said. “No,” he declared under questioning on Sunday evening, “I have not.” At that moment, sitting at home in Manhattan, Jessica Leeds, 74, felt he was lying to her face. “I wanted to punch the screen,” she said in an interview in her apartment. More than three decades ago, when she was a traveling businesswoman at a paper company, Ms. Leeds said, she sat beside Mr. Trump in...