It's not just racism. "China will steal our Siberia" has been a boogeyman/talking point in Russia for as long as I remember - so probably even before the USSR collapse.

And you're right. Material conditions matter. So what do the people see? They see China that is growing richer and more powerful with every passing day, while their own conditions worsen. Do you expect the reasoning to be "we should do what they do", or will it be "they're leeching off our wealth and grow fat off our blood"? You know, like Europe was doing for thirty years.

It honestly might just be due to racism (and other phobias). Far right parties are able to get people to vote against their own interests by centring “the other” as the issue rather than the system; the white working class (not all of them, of course) are ensnared in this trap, their racism used as an advantage. These parties use that racism to cloud the real problems and convince the white worker to blame non-white people as the origin of the economic disaster they are facing. It is not the system, but the people in the system. Other minorities (gender and sexuality) are used in this way as well. It is very hard to understand this view but it happens, some people will not come out of it until they see the problems persisting even after every minority is gone.