@Iwasafool I think you're right.
That did also play a part. The LA cops were horrifically racist and the capturing on video of the Rodney King meant that everyone saw that.
Much like Brexit gave neglected and taken-for-granted voters a chance (as they saw it) to stick 2 fingers up to the establishment which they correctly saw had let them down (without necessarily knowing the effects a Leave vote would have), the OJ trial was seen by many black people, including jurors, to stick 2 fingers up what they saw (largely correctly) as a racist, corrupt justice system.
They knew that the police routinely lied and beat up innocent black men. That would have made it easier to believe that they had framed OJ.
Tribalism played a part, just as it does in today's identity politics.
I do think that his status as a wealthy, successful sportsman will also have played a part.
His wife, a victim of repeated domestic violence didn't have any justice while she was alive and she and her friend didn't get any justice after their deaths because OJ got away with double murder.