Please don't explain what you mean by "their own racism". I don't accept reverse racism BS...
And yes, ignoring nasty history is dog-whistling. You can say certain things, which are clearly perceived as racist by racists and the offended, and then avoid responsibility by claiming "it's only because the history".
Example: It's not antisemitic to blame George Soros (a jew) for political influence through his money, except that there is a broad and infamous history of such conspiracy theories. Same for "dual loyalty".
It's not racist or insensitive to use black-face as a disguise, except for the long history of mistrel-acts of making fun of Afro-American (slaves) for being lazy, uncultured and stupid.
It's not necessarily racist to suspect a Muslim of being a terrorist. Hey, there may actually be valid and objective reasons for such a suspicion. But especially because of the context and the history of Muslims being accosted as such and being targeted all the time, such claims better have substantial proof.
There is, however, a phenomenon called "reverse racism" where privileged members of a majority try to complain about things like affirmative action or diversity outreach.
The idea that there is a discrimination against white people in "traditionally white" countries is absolutely ridiculous. Ethnically motivated violence, for example in the US, is also quite one-sided.
One shouldn't use history to justify their own racism.
> Racists can often behind ignoring that distinction. It's called a dog-whistle.
That's simply not what a dog-whistle is.