Only some countries have visa problems. Canadians, for example, probably fall under the TN/Nafta visa system which can get them over the border relatively quickly (although not on the clock for permanent residency). I think there are similar programs for there Western Hemisphere countries (there are in Canada, for example). Canadians are probably ignored by the "voting public has difficulty with any immigration" as they're probably seen as part US anyway.

Western Europeans, while requiring a visa, probably are also agreeable due to melanin content and similar social frameworks. Central and Eastern Europeans might be more palatable due to more-similar political philosophy to the aforementioned group. Asians, however, have issues in various areas and Chinese in particular are a sensitive issue right now.

So, if you want to staff more cheaply there's probably visa issues that will get in the way. If you want to staff with a bit more cost, it might be more straightforward. Depends on what you're looking to hire. The other option, I guess, would be to develop a tax nexus outside the us to circumvent both US salary scales and immigration.

A large portion of the voting public has difficulty with any immigration. The feedback from very strict immigration to problems is very long. The same voting public does not trust experts. Seems like a very hard problem to solve