A debating opponent of the leftwing media figure Mehdi Hasan in a controversial viral YouTube video was previously the organizer of two violent far-right protests in Berkeley, California in 2017, the Guardian can reveal. The video debate session with Hasan, published to the 10 million-subscriber Jubilee channel, has already attracted scrutiny due to platforming a self-described “fascist”, Connor Estelle, who reportedly lost his job after he was identified by online researchers. Unidentified until now was another of Hasan’s opponents in the debate video, Richard Black. In conversation with Hasan, Black refused to condemn violence against police officers, claimed that the...