Over the weekend in London, tens of thousands of people took to the streets for the anti-immigrant “Unite the Kingdom” rally organized by far-right activist Tommy Robinson, featuring Elon Musk as a guest speaker. Elizabeth Pearson, who researches the far-right in the UK, helped situate the rally in the context of British social movements and politics. Pearson is the author of “Extreme Britain: Gender, Masculinity and Radicalisation.”