I think that doubt prevailed over prejudice of individual jurors. What's really interesting about the case within 12 Angry Men is that we never ultimately find out for sure whether the accused is guilty or innocent. While much of the evidence is aptly questioned and manipulated by 8th Juror, at the end of the case there remains a tremendous amount of evidence built up against the accused. Still, it is "beyond a reasonable doubt" that the jurors must find the accused guilty in order to convict him, and they all ultimately come to the conclusion that they have at least some doubt. We leave the play with a sense that justice and right has prevailed over irrationality and prejudice, but, pointedly so, we never actually find out the truth. This doubt over who is on the "right" side pervades the psychologies of the characters in the play and any audience watching.