Being racist doesn't (just) mean you call people slurs on the street. Being racist / racism describes racially oppressive systems within society and how people are raised in it and influenced by it. Just the way people in this thread are talking about how many people in China grow up under X circumstances and thus believe Y. I know that popular belief is that to call someone racist pretty much means 'that person is morally bad', for the obvious reason that racism is bad, but I think it's more important to talk about the issue of how and why than to use "this person / X people are racist" as some kind of blame game or moral condemnation.

So when someone says half of America is racist, I don't think this means they're saying half of America secretly gets in KKK outfits at night, I think it means there are racist things in society that everybody subconsciously learns on BOTH sides of the political spectrum (thus, it would be more than half of America, honestly).

At least, that's what I think when someone says half/a third/the whole country is racist.