Every nation or races are proud with their own race. US people are proud with being US people. Chinese, Arab, Japanese, etc etc. So because of that, sometimes they see the others lower than themselves. This is natural, because everybody are like that, including me.
So after seeing your own race is being harrassed or displayed as a bad figure, it is ok if you are mad or angry. Just for example after reading school rumble, you see your own race are displayed as arrogant, bad-ass and bad people, then you get angry, it is okay. It means you are really proud with your race, and i think it is a good thing. Although some people might misunderstand it