"This is what happens when not just Trump, but much of the Republican Party leadership, in a polarized political setting, spends four years lying to its base — working its base into a frenzy telling its base that the other side are traitors, that the other side are trying to destroy the country, that the other side stole the election. If you spend four years mobilizing the base into outrage, you’re very likely to get this sort of violent mobilization."