Nassim Taleb talks about a similar phenomenon in “Skin in the Game.” His proposition is that there are cases where a minority’s needs or values might be small relatively speaking but the cost of not accommodating them is more than that of not doing so so the niche becomes mainstream for something akin to economic forces. I listened to the audiobook so don’t have access to his sources but it might be a better place to start looking for more credible research into this idea of anyone is interested.
You are talking about his idea of "the intolerant minority", but it has nothing to do with over- or under-representation of people in certain demographics.
If anything, it is almost the opposite. The idea is that intolerant minorities can get to have their preferences dominate if they are more-or-less evenly dispersed among the larger population.
