Cohen, according to organisers of the event, was a late sponsor of the rally and offered up to hire his own personal security.
Also Read: Sacha Baron Cohen Rips Google Co-Founders for Resignations: 'Now You Drop Out?' The Washington 3% group quickly took to Facebook to denounce Sacha Baron Cohen's stunt.
After video footage spread on social media, Variety later confirmed that the singer was in fact Baron Cohen. As the crowd got attuned to the lyrics, Cohen sang "W H O what we gonna do", and asked the crowd whether they'd like to "inject them with the Wuhan flu" or "chop them up like the Saudis do" - the crowd in unison chose the second option. "His security blocked event organizers from getting him off the stage, or pulling power from the generator".
Then he began singing a catchy song whose lyrics included racist language and antisemitic conspiracy theories popular among far-right extremists.
A video of the performance includes audio of members of the crowd joining Baron Cohen's call-and-response routine. Inject him with the Wuhan flu", "Hillary Clinton, what we gonna do?
Cohen reportedly contacted organisers - the far-right group Washington Three Percenters - a week ago, offering to provide sponsorship and entertainment for the event.
The group says on its website that it is "a national organization made up of patriotic citizens who love their country, their freedoms, and their liberty". The website includes a vehement denial that racism, or anti-government sentiment, play any part in its ideology.
Cohen hasn't publicly commented on the prank yet, but we're guessing there's a good chance it'll find a place on his political satire TV series, Who Is America?.
"After the crowd realized what he was saying, and turned on him, his security then rushed the stage and evacuated them to a waiting private ambulance that was contracted to be their escape transport", Blair added.