You say this as if racism and economics aren't directly linked. Think about it for a moment. Racism has always served economic purposes in slavery, cololization, resource extraction and poverty. It's quite obviously in the self-interest of the dominating party.
Most (if not all) motivations for slavery, colonization and resource extraction have been economically related, but that's not to say that all economic decisions are based in racism.
Generally the answer to every problem in every other Country isn't to just ship them to your Country, that's an unsustainable model. Typically the people who migrate are either young, well educated or wealthy - which in the grand scheme of things does nothing to fix the problems in their originating Countries.
I hope you see the irony in downplaying economic motivations as merely related and then making an economic argument against immigration that most racists agree with.
If I choose to fire somebody of a different race because they got naked and ran around the office - it isn't racist just because racists agree with the action I took.
