Of course in many such cases, notably the US and Poland itself, those issues seem to revolve heavily around hatred of immigrants and asserting a racist nationalism of an extreme variety. What is more this has often involved making exaggerated, if not downright incorrect, claims about the impact of immigrants on national economies. This becomes especially unsophisticated when those making these appeals outright lie about the state of the economy, declaring that the economy is in much worse shape than it is and then blaming the supposed terrible shape on the immigrants.
Thus in the US we had Trump claiming that improving employment numbers were fake news, and that the BLS was engaging in fraudulent and inaccurate measuring and reporting of the improving employment numbers. Then, of course, the supposedly much worse employment situation in the US that we really had according to him was mostly due to immigrants coming in and taking jobs (he was more accurate in his complaints that in Midwestern rust belt loss of manufacturing jobs was partly due to imports). Then the minute he got in office and the employment situation continued to improve at about the rate it had been doing so, well, all of a sudden the BLS was accurate, and the improving employment situation was all due to him, as was the rising stock market he had previously ignored was suddenly the most important thing around.
The irony in this particular situation is that the US’s Poland problem has come back to bite Trump. Even though indeed the economy is continuing to improve since Trump has taken power, it is not helping Trump at the polls at all, with him having the lowest poll ratings for a new president we have seen since reliable polling began. Some of that is indeed that people do not believe he has had much to do with the state of the economy so far, but probably most of it is simply people focusing on the other things he is doing, including the extreme racism of his anti-immigrant policy, which has ceased to be the vote getter it was earlier.