Watching a racist liar get systematically dismantled in a courtroom would be undeniably cathartic for anyone who's had to listen to Donald Trump's husky whine over the past year, so it's a shame that this satisfaction must be wedded to a film as inert as Denial. People who complained that Clint Eastwood's Sully practically got a hernia straining to turn the Miracle on the Hudson into a film-worthy drama should stay far away from Mick Jackson's film, which tells a story so straightforward that it makes Sully look like a Shyamalan thriller.

The true-to-life story centers on the libel trial of American professor Deborah Lipstadt (Rachel Weisz), who is sued by the British Hitler apologist David Irving (Timothy Spall) after she publishes a book that calls him a Holocaust denier. It's a frivolous lawsuit, of course, but because of the guilty-until-proven-innocent standards of the British civil-court system, the burden of proof is on Lipstadt, not Irving. Cue the standard courtroom-drama tropes: early setbacks, dramatic witness-stand confrontations, and the breathless moment before the verdict is read.

Denial takes its sweet time getting to those moments. The first act is dull even by the standards of legal procedurals, devoting much of its time to interminable scenes of characters reassuring one another that they all agree the Holocaust happened. It's a relief once the trial begins, because at least then there's a good reason for all the exhaustive exposition. But even once Denial arrives at that point, David Hare's screenplay never succeeds at finding a compelling reason for the story to be retold like this. Irving is so transparently bigoted and so easily outfoxed by Lipstadt's lawyers that most suspense simply evaporates out of the courtroom. Decades of books and movies about the Holocaust have ensured that Denial's perfunctory attempts to evoke Nazism's horrors read as toothless and facile. Jackson and Hare have made a film for viewers who already affirm the historicity of the Holocaust, but ironically, the only people who would find anything truly surprising about this film would be Holocaust deniers.

To their credit, Jackson and Hare seem to realize this problem at some level. What emerges as the film's central conflict is Lipstadt's struggle with her conscience—as a Jew, she has a deeply personal stake in speaking out against Irving's falsifications, but her best chance at defeating him in court depends on her (and her fellow Jews) staying silent and letting her lawyers do the dirty work. The film's sole compelling moments come when this inner conflict is brought to the fore. In conversation with one of her attorneys (an excellent Tom Wilkinson), Lipstadt tells him, "You have no idea how hard it is to give control of your conscience to someone else." In such moments the film is asking a provocative question: Has true social justice been achieved if it does not allow the marginalized to speak on their own behalf? Is it right to expect the Jews to stand by and keep their mouths shut while other people deliberate over whether society will accept the validity of their suffering? The parallels with contemporary discourse surrounding social movements such as Black Lives Matter are obvious.

It's too bad, then, that Denial lacks the imagination to drill deep into this idea and extract something complex from it. Very little in the performances or staid cinematography does anything to add dimension to the film's convention-bound story. When it comes time for the dramatic climax, Lipstadt seems to have forgotten her angst over her passive role in the courtroom; meanwhile, director Jackson includes an extremely ill-considered shot of a Holocaust survivor gazing approvingly at Lipstadt and her legal team. (The implication, of course, is that the survivor's earlier pleas for a voice were just as weightless as the rest of the film.) Jackson further fumbles the ball in the denouement, in which Lipstadt and her lawyers watch the mendacious Irving give a television interview after the verdict. Their reaction is a scornful dismissal: they switch off the news, and Irving disappears.

It's a tidy and theoretically satisfying ending, but it sticks in the throat. We have witnessed firsthand a year in which a carrot-colored TV charlatan has come to the threshold of the United States presidency primarily by shouting lies and invective in such profusion that it's a full-time job just to refute each new falsehood. Scornful dismissal has done little to derail or even slow his progress. The tenacity of his followers' support even in the face of clear-cut evidence of his misogyny and ignorance suggests that there's something sick in humanity. People are only too happy to deny the truth when it suits their agendas or prejudices, and not all of these people are oily villains like David Irving or thunderous ignoramuses like Donald Trump. This is the reality that we must acknowledge, and it's a reality that Denial's final shot gestures at but does not touch.