Look! It's about how much an immigrant looks like the locals, and acts like everyone else. I could say the same thing about how Italians were treated where I grew up, when in my childhood, the first generation of Italian immigrants that were getting up in years, spoke little if any English, and took labourer jobs where it didn't much matter, since they were mostly pick and shovel jobs. They lived in a segregated little Italy neighbourhood, and didn't mix with the rest of the community. By the 2nd and 3rd generations, as some of their children became educated and established professionals, and more immigration loosened the parameters for what qualified as "white," the Italians started losing their language and connection to the old country.
And, what also happens during this process of a minority group going from disparaged outsiders to cornerstones of the community, is that they take on the thinking and attitudes that prevail in the community. So, even when I was young, Italians were a Liberal block vote, and didn't start drifting away from Liberal Party politics until less than 40 years ago. Same thing happened in the U.S., where those same Italian and Eastern European immigrants became the "Reagan Democrats" of the 80's.
So, when we are talking about someone like George Zimmerman, who is only half Latino on his mother's side and has a former judge for a father, and lives in a white community, not some Spanish-speaking ghetto, he is "white" enough for everyone on the right to make him one of their own lately. And though they don't consider Zimmerman white enough to qualify for membership in their club, the Nazis see his community as their people:
Armed Neo-Nazis Now Patrolling Sanford, Say They Are "Prepared" For Post-Trayvon Martin Violence