The murder of George Floyd, at the hands of the Minneapolis police on 25 May, might at the time have seemed just one more dreadful case in the long and sadly routine litany of Black people being killed by US police. But something about this needless and cruel death, widely documented and shared on social media, in a year of particularly toxic US politics, and at a time when people were being told to respect pandemic rules and the authorities enforcing them, resonated.