Parker was heard occasionally on radio, including
Information Please (as a guest) and
Author, Author (as a regular panelist). She wrote for the
Columbia Workshop, and both Ilka Chase and Tallulah Bankhead used her material for radio monologues.
Parker was listed as a Communist by the publication
Red Channels in 1950. The FBI compiled a 1,000-page dossier on her because of her suspected involvement in Communism during the McCarthy era. As a result, she was placed on the Hollywood blacklist by the movie studio bosses.
In 1952 Parker moved back to New York, into the Volney residential hotel. She drew upon her experiences there to co-write, with Arnaud d'Usseau, the play
Ladies of the Corridor. The play opened in October 1953 to uneven reviews and closed after six weeks.
From 1957 to 1962 she wrote book reviews for
Esquire, though these pieces were increasingly erratic owing to her continued abuse of alcohol. One of these reviews had a huge impact on the career of the young Harlan Ellison. Reviewing his paperback short story collection
Gentleman Junkie and Other Stories of the Hung-Up Generation (Regency, 1961), she described Ellison as "a good, clean, honest writer, putting down what he has seen and known and no sensationalism about it" and lavished praise on his story "Daniel White for the Greater Good," commenting, "It is without exception the best presentation I have ever seen of present racial conditions in the South and of those who try to alleviate them. I cannot recommend it too vehemently.... Incidentally, the other stories in Mr. Ellison's book are not so dusty, either." Her favorable nod gave Ellison a foothold with both mainstream publishers and film producers, and shortly afterwards he headed for Hollywood.
In 1961 Parker returned to Hollywood and reconciled with Campbell. They worked together on a number of unproduced projects; among her last was an unproduced film for Marilyn Monroe. Parker found Campbell dead in their home in 1963, a suicide by drug overdose.
Following Campbell's death, Parker returned to New York City and the Volney. In her later years, she would come to denigrate the group that had brought her such early notoriety, the Algonquin Round Table:
These were no giants. Think who was writing in those days--Lardner, Fitzgerald, Faulkner and Hemingway. Those were the real giants. The Round Table was just a lot of people telling jokes and telling each other how good they were. Just a bunch of loudmouths showing off, saving their gags for days, waiting for a chance to spring them.... There was no truth in anything they said. It was the terrible day of the wisecrack, so there didn't have to be any truth....
Parker died of a heart attack at the age of 73 in 1967. In her will, she bequeathed her estate to the Dr. Martin Luther King, Jr. foundation. Following King's death, her estate was passed on to the NAACP. Her executrix, Lillian Hellman, bitterly but unsuccessfully contested this disposition. Her ashes remained unclaimed in various places, including her attorney Paul O'Dwyer's filing cabinet, for approximately 17 years.