Picking up Decca: The Letters of Jessica Mitford (Knopf, 2006), a 744-page collection of Mitford's letters edited by former SF Chronicle staffer Peter Y. Sussman, I've gained even more respect for her.
Mitford was one of five well-known daughters born to Lord and Lady Redesdale in Oxfordshire, England who took wildly different paths. Two of her sisters became Nazi sympathizers; Jessica ran off at the age of 19 with her second cousin Esmond Romilly, whom she married and joined chronicling the Spanish Civil War. Romilly died in WWII while flying for the Royal Canadian Air Force, and Jessica married labor lawyer Robert Truehaft and lived in Oakland, CA until her death in 1996.
The couple was eavesdropped on by the same FBI agents who later targeted Mario Savio and student activists in Berkeley; Ronald Reagan got reports on her and Mitford later joked when she donated eyeglasses to a museum not to put them near Reagan’s for fear of explosion. She was good friends with Tokin' Woman Maya Angelou, and helped her husband Bob defend “Negroes” falsely accused of murder and rape, explaining to her mother (“Muv" = Lady Redesdale) in a letter what a “frame up” was and how it was applied to Negroes especially.
She also testified at a hearing in front of Sen. Edward Kennedy in DC about drug experiments taking place on California prisoners (“Cheaper than Chimpanzees” was her headline). As well as exposing the funeral industry in her famous book The American Way of Death, she wrote an exposé of the US prison system (Kind and Usual Punishment: The Prison Business (1973).
Long before it was fashionable to do so, Mitford documented the racial disparity in prison time for crimes between whites and people of color, noting that in drug cases, the average sentence for whites was 61.1 months, and for nonwhites 81.1 months. She also calls out New York's Governor Rockefeller on his absurd "solution" to the drug problem: locking up for life the dealers of all drugs, including hashish but excluding marijuana. She quotes Pennsylvania inmate Samuel Jordan, who wondered, "Could this be because he does not want to see his pot-smoking young relatives behind bars?"
On May 4, 1967 Decca wrote to her sister Nancy Mitford from Oakland (in a letter describing having Arnold Toynbee over to dinner and Bob’s “re-torturing” of the CIA over their involvement in the Berkeley Co-op movement) she talks about what her "Muv" called "Marriage Uana":
Hillary Clinton interned with Mitford's husband in the 60s while she was a Yale law student, but here's what Mitford had to say about Bill Clinton in 1992:
I'm not the only one who admires Mitford: J.K. Rowling named her daughter after Jessica.
*I can't however find the source of that quote, although she did say, "If to be objective means having no point of view, or giving equal weight to all information that comes one's way, I plead guilty—although accuracy is essential...