It's impossible to exonerate the internet, and social media in particular here. It allowed for the efficient networking and ratcheting-up of our worst impulses at unbelievable speed and scale. In-group/out-group dynamics are as old as the hills, but social media is a particle accelerator for them.
CalliopeMore to the point, this is happening in *non-white* countries as well: Japan, Turkey, and India have huge far-right nativist blocs. So it's not merely white supremacy or nostalgia for the days when the West ruled. Nor is it happening purely in developed post-material countries.