Kitt was also a member of the Women's International League for Peace and Freedom; her criticism of the Vietnam War and its connection to poverty and racial unrest in 1968 can be seen as part of a larger commitment to peace activism.[46] Like many politically active public figures of her time, Kitt was under surveillance by the CIA, beginning in 1956. After The New York Times discovered the CIA file on Kitt in 1975, she granted the paper permission to print portions of the report, stating: "I have nothing to be afraid of and I have nothing to hide."

Kitt later became a vocal advocate for LGBT rights and publicly supported same-sex marriage, which she considered a civil right. She had been quoted as saying: "I support it [gay marriage] because we're asking for the same thing. If I have a partner and something happens to me, I want that partner to enjoy the benefits of what we have reaped together. It's a civil-rights thing, isn't it?" Kitt famously appeared at many LGBT fundraisers, including a mega event in Baltimore, Maryland, with George Burns and Jimmy James. Scott Sherman, an agent at Atlantic Entertainment Group, stated: "Eartha Kitt is fantastic... appears at so many LGBT events in support of civil rights." In a 1992 interview with Dr. Anthony Clare, Kitt spoke about her gay following, saying:

"We're all rejected people, we know what it is to be refused, we know what it is to be oppressed, depressed, and then, accused, and I am very much cognizant of that feeling. Nothing in the world is more painful than rejection. I am a rejected, oppressed person, and so I understand them, as best as I can, even though I am a heterosexual."
(Wikipedia)

Because there’s no one who can capture her essence.

Not sure. I always had a crush on her as a kid.

Who would we cast?

https://www.imdb.com/name/nm0457755/bio/