The nationalist element of Brexit populism had an entrenched ethnocentric character that was capable of breaking out in the in the form of racism. By 2016 overt racism had become taboo in public, but Brexitspeak had the linguistic means to dog whistle it. The new racism also enlarged the sense of ‘racism’ to cover refugee migrants entering the UK who were not dark-skinned. The sources of racism in the UK are diverse and subject to debate. In this chapter the focus is on the likely impact of racist demagoguery in generating and sustaining long-term racist attitudes. The example of Enoch Powell and his ‘rivers of blood’ speech is scrutinised in detail. But Powellism persisted well beyond the 1960s and 1970s: twenty years on it motivated the murder of Stephen Lawrence. In the age of the internet, Powell was a legitimising icon among neo-Nazi networks and appeared in website videos quoting and visualising his notorious speech. But veneration of Powell also remained apparent among right-wing Conservative politicians, activists and writers, and in their networking with ultra-right individuals.