In 2016, the impeachment trial of Brazil’s first female president, Dilma Rousseff, began. She was accused of breaking budgetary laws, but in the midst of the ongoing Operation Car Wash corruption scandal, her supporters argued that the real motivation behind the proceeding was political, not legal. In this film, completed before Bolsonaro’s rise to power, director Maria August takes us back through the strangely staid series of rulings. Is a coup is still a coup when it follows “due process”?

Ramos’s wholly observational technique – no interviews, no narration – assumes a good deal of prior knowledge on behalf of the audience. We’re left to infer the identities and allegiances of key players, yet some international parallels are recognisable, even when the particulars of Brazilian politics are not. It is easy to imagine, for instance, that Hillary Clinton staffers might nod along with Rousseff’s observations about how society’s latent misogyny shows up at the ballot box.

This approach also means we’re reliant on whatever showmanship the trial’s participants might possess to keep us entertained during the lengthy running time. Two, in particular, provide: attorney Janaína Paschoal’s demagogic oratory requires that she limber up with some stretches before delivering a testimony, which typically culminates in a patriotic and teary outburst. José Eduardo Cardozo, on the other hand, remains largely unmoved by such shenanigans. As attorney-general he’s the withering wit charged with pointing out illogic, whenever it may occur.

For the most part, though, it’s dry stuff. Suit-wearers sitting in boardrooms and offices talking on mobile phones; TV news crews setting up tripods in quiet corridors; slow-moving traffic in front of Brasília’s parliamentary building. There is a warning contained here: not all power grabs are the stuff of drama. Indeed, perhaps, it is the slow, steady kind that represent the most serious threat to democracy.

• The Trial is available on Mubi from 18 August.