The invisibility of whiteness means that one doesn't have to notice that one is white. So there are people, and then there are black people. There are people and there are Latino people. And people—just people, just folks—turn out to be white, but we don't notice it.
White people have the luxury of not having to think about race. That is a benefit of being white, of being part of the dominant group. Just like men don't have to think about gender. The system works for you, and you don't have to think about it.
So they live in white space and then they don't have to think about it. First of all, they think about race as something that belongs to somebody else. The blacks have race; maybe Latinos have race; maybe Asians have race. But they're just white. They're just people. That's part of being white.