Considering all the work Mercedes McCambridge put into The Exorcist, it’s hard to believe she would have refused credit for it. In any case, Warner Bros. finally gave her on-screen credit after more prints of the film were released to theaters. Even so, McCambridge was given a generic credit line — "And Mercedes McCambridge" — which failed to specify, as the actress had requested, her performance as the voice of the demon.
Linda Blair’s Oscar nomination came after the McCambridge controversy, possibly because enough Academy members were unaware of McCambridge’s crucial assistance to Blair’s on-screen effectiveness. But then came another revelation — technically quite similar to the one currently pitting Black Swan’s dance double Sarah Lane against the film’s star, Natalie Portman, but more damning in that it directly undermined what had been perceived as Blair’s (physical) dramatic prowess:
"… [I]t seems that the Devil may be claiming his due," added the February 25 Time report. "Doubts are being raised as to how much of the role was performed by 15-year-old Linda [actually 13 or so when the movie was made]. First, there was Mercedes McCambridge, whose bloodcurdling Devil-in-Linda voice would have gone unrecognized if she had not fought for screen billing.
"Now comes Eileen Dietz Elber, who was Linda’s double. Eileen, who describes herself as ’over 21,’ charges that Friedkin tried to prevent her from taking credit even on job resumes for her role as Linda’s body in the movie’s major dramatic moments. In the face of Warner’s denial, she insists: ’I shot several exorcism scenes and played nearly all the vomit scenes.’ Added Eileen: ’If Linda wins an Oscar, I’ll be the first to cheer.’"
There was no cheering, as the Best Supporting Actress that year went to Paper Moon’s nine-year-old Tatum O’Neal, who did her own smoking and delivered the line "I need to go to the shithouse" without a voice double.
Mercedes McCambridge quote: Damien Bona and Mason Wiley’s Inside Oscar.