Australia has 83%+ (with 67% being of British ancestry) and UK has 86% white population while US has 60% non-hispanic white population (with no such single major ancestry inside it like the British ancestry of the AU and UK white populations). Thus there are huge sources of racist/xenophobic voting power drivers that the right-wings in AU and UK can tap into while doing so in US causes blowback of similar scale and which grows with voting participation increase.