If all mankind minus one, were of one opinion, and only one person were of the contrary opinion, mankind would be no more justified in silencing that one person, than he, if had the power, would be justified in silencing mankind.This made me think of various ways that our modern society has of shaming people into not talking. One way that seems to be common in social or political arguments is to simply disqualify people if they aren't from the proper background. I'm speaking of the argument that your sex, color or social status somehow decides whether or not what you're saying is valid.
If we take a step back, then of course those things make no difference. The above statement from Mill would be just as true, or just as false, coming from a man or a woman. It would not change depending on the race of the speaker or whether or not their parents were rich or poor. It would only hinge on the inherent value of the proposition.
Which isn't to say that we can't take the background of the speaker into account. Statements on poverty, for example, should be given more weight from people that have experienced it. Same goes for statements on discrimination and culture and so on. But at no point should we simply shut someone up because they don't check the right boxes on the scorecard.