I really don't think I'm misunderstanding you here--I think you're not expressing yourself precisely.

You didn't, in your introduction, qualify that you were speaking only about the personal experience of categorical mistrust. Not only did you say "racial issues", which is broader (and for which the other lines of evidence I gave are also relevant), you also don't appear to restrict yourself in this way.

For instance, when you justify the prejudicial attitude, you say, "being forced to interact with people who might be dangerous requires a default assumption of danger until proven otherwise". But if you are relying solely on first-person accounts, there is another possibility: the danger is not real but is a socially-constructed phantom, like voting fraud. In this case, the reaction is not justified--what is justified is to fix the incorrect socially-constructed phantom.

But now the entire structure of your argument becomes hard to follow. You explicitly disavow lines of reasoning that you seem to explicitly use.

The reason this is critical is that there is a tendency in arguments like this to wander back and forth between subjective feeling (which can't easily be argued--you'd need an implicit association test or somesuch) and objective truth (which can).

Because your conclusion is rather counterintuitive as stated (though it might not be if you had generalized), it's especially important for the logical structure to be clear (and valid, and sound).