When people feel victimized by what other people are saying than this will cause others to react to them reacting. The more everyone (minorities included) in America and other countries whines about how much they get picked on, the more they are putting themselves out there as being different.

The more they whine, and the more they put themselves out there, the more everyone else will think they are different.

So racism aside, here's an example (don't get offended by an example geez):

Some Black people may get offended by something some white dude said. This in turn causes those white guys to further say things in response to the black guys getting offended and it goes on and on. The more this goes on, the more victimized the black guys feel, and the stronger the opinions (good or bad) of the white guys goes about the black guys.

Irish for example. In (I want to say) early 1920s, the Irish started coming to America. At first, they for quite a long time they were subjected to a lot of hatred. These "Potato-lovers" (Potato's are great btw) reacted with riots and pickets and the like. By doing all of this, they weren't causing the opinions of others to be swayed for the better, they were in fact causing it to get worse.

Same with early history of Asians in America, this whole Muslim terror group shit, and other groups.

Extremism and activist movements don't improve the standing of anyone, but they certainly make people dislike you (and since you're with multiple other people that many people can't distinguish) as well as others of your "group".

Racism is pointless in my opinion, and extremism (except in a few cases that I won't mention) even more so.

Scientifically (and evolutionary) speaking, I can see how holding physical differences against others might have have saved you and allowed humans to survive longer, but these days it's pretty pointless.