Left-wing radicals have been mobilizing near the nation’s capital ahead of the January 20 inauguration, which has been moved indoors. Since summer, we have tracked D.C.’s radical networks—their movements, methods, and potential for violence. After George Floyd’s death in 2020, these groups learned that street protests could yield political gains. Now, with Donald Trump returning to the White House, they’re weighing their options. This network is decentralized, adaptable, and steeped in organizing social unrest. Black Lives Matter messaging is fading, replaced by anti-Israel rhetoric. As Inauguration Day approaches, Communist militants and members of Antifa-aligned hubs have suggested storming the Capitol,...