When whites hate whites, why is it called racism?

Racism= the hating of someone because of their skin color.

That is why a black person from outside of America will endure racism just the same as blacks inside of America.

But I'll tell you what is NOT racism.

When a white person hates another white simply because they come from another country.

Case in point: The Irish. White America is guilty of oppressing everyone....but how they oppress them is quite different.

What the Irish were experiencing was Xenophobia. By definition, one could say that racism and even sexism is a form of xenophobia, as the definition just simply means hating something that is different from one's self.

But in the end, its not racist for an English white to hate an Irish white because racism has to do with one's race, which means their skin color. And BOTH are white.