"Had the magazine been aware of this relationship, she would not have continued to cover the presidential campaign," New York magazine said in a statement.
The 76-year-old man is accused of sending more than 465 messages, including threats of assassination and torture coupled with racist and homophobic rhetoric.
The GOP gubernatorial candidate allegedly called himself a "black NAZI" and said he liked transgender porn years ago, despite his recent anti-trans rhetoric.
The North Carolina gubernatorial nominee, known for his sexist and transphobic rhetoric, also allegedly spied on women in showers and digs transgender porn.