The Miners are not mining to dominate the world, they are mining to make profits. The two biggest users of Bitcoin is the USA and China at the
moment, why would they stop accepting tx's from US users, and cut their profits in half, and possibly become unsustainable? Even if this was
possible, it would push business into the pockets of other nations/global miners.

They might not reject these transactions altogether, they might just increase the fees exactly by the amount that Trump sets his protective tariffs to for the Chinese goods exported to the US markets, i.e. accept certain transactions only if they have a high enough fee. If your country has been openly accused with stealing jobs ("They're using our country as a piggy bank to rebuild China"), would you be quite happy with that? When, in fact, it was the American companies which moved their production to China in the first place. Would you quite like it when your country has been mentioned along with the Islamic State ("We've got to deal with ISIS. We've got to deal with China")?
What does China have to do with ISIS after all?