BlacKkKlansman begins with Vivien Leigh as Scarlett O’Hara in Gone with the Wind (1939), picking her way through a mire of injured Confederate soldiers. Then it cuts to Alec Baldwin as a fictional mid-twentieth-century eugenicist spewing racist pejoratives and bilge about ‘the International Jewish Conspiracy’. Footage from D.W. Griffith’s profoundly racist and egregiously influential film The Birth of a Nation (1915) is projected across his face. Baldwin is noted for his Saturday Night Live caricatures of contemporary American racist Donald Trump, and BlacKkKlansman’s director, Spike Lee, is banking on that recognition. The slippage between personages, images, and decades is a part of his strategy. Are we watching a bigoted artefact from the distant past, or yesterday’s Fox News?

BlacKkKlansman is many things: a caper; a cop flick; a polemic; a critique of US cinema’s foundational racism; a homage to Blaxploitation films of the 1970s, and, finally, a tragedy. It is also a tall tale that mostly happens to be true. Cut to Colorado Springs, Colorado, in some unspecified year in the 1970s, where Ron Stallworth (John David Washington) – a rookie cop, an aspiring undercover detective, and the only black man on the force – is about to make contact, practically on a whim, with the local chapter of the Ku Klux Klan.

This really happened. The film’s four credited screenwriters, including Lee, based the main part of their script upon the real Ron Stallworth’s memoir of his time infiltrating the Klan. It is such an unlikely premise that Lee can make from it a trenchant yet surreal comedy. Fluent, as he boasts, in both ‘King’s English and jive’, Stallworth poses on the phone as a white supremacist, while face-to-face meetings with Klan members are handled by Stallworth’s colleague Philip ‘Flip’ Zimmerman (Adam Driver), who pretends to be a white Stallworth. Flip also happens to be a non-practising Jew, who finds himself having to deny that heritage to gun-wielding, anti-Semitic cranks. ‘You’ve been passing for a WASP,’ Ron comments to Flip. ‘It’s what some light-skinned black folks do: they pass for white.’