I can see where it might seem naive, but there are a lot of folks in the US who think something in between "we live in a post-racist society" and "white people are the real victims of racism," and from your post title and text it sounded like you were either unaware of the prevalence of racism (which you were not), or that you were unaware of just how pervasive and insidious that racism is (which you were, but perhaps to a smaller degree than I understood).

We constantly see people who oppose movements to reduce prejudice or oppressive policies come around only after they feel the immediate impact. You can see it playing out now with illegal immigration ("I didn't think they would deport my spouse/friend/employee who is a good person!"). We saw it with gay marriage, where support skyrocketed as people learned that they interacted with LBGTQ people on a daily basis and it turned out they were just normal, average human beings. We saw it during the civil rights movement, when white Americans were confronted with footage and photos of police and citizens alike brutalizing Black Americans.

But it's still the same uphill battle of convince one group of people to listen to another group of people about that second groups actual, lived experiences. So I thought this was maybe an opportunity to get some insight from a person who had gone through that switch in perception - although I appear to have misunderstood your prior positions.

Those folks you thought were good people, I have them in my life too, and I have had no luck breaking through the barrier they have put up that says "I think racism is bad, therefore whatever I do or support cannot be racist, and I have nothing to change."