Nixon earned Tony Awards for her turns in Rabbit Hole and The Little Foxes. She has also been seen on Broadway in The Philadelphia Story, Hurlyburly, The Heidi Chronicles, Angels in America, Indiscretions, The Last Night of Ballyhoo, The Women, Wit and The Real Thing. Nixon won Emmy Awards for her performances on Sex and the City and Law & Order: Special Victims Unit. A native New Yorker, Nixon has remained heavily involved in politics throughout her career. She is a vocal advocate on issues including LGBT equality, public education and reproductive rights.