After Adam McKay explained the 2008 financial crisis—or, at least, a particularly sinister facet of it—with The Big Short, and was rewarded with a screenplay Oscar for his troubles, it makes sense that he’d want to return to the well of recent history to educate us on something else. With much to rummage through, he found a singularly opaque subject to dust off and, if not polish, at least grace with the glow of cinematic attention. That subject is none other than the ghoul of the aughts Dick Cheney: the sinister machinator behind the ruinous presidential administration of George W. Bush.

McKay’s new film about former Vice President Cheney’s rise to power, rather bluntly titled Vice, takes the bold position that Cheney—a shadowy puppeteer pulling the strings of the president and thus of the world—was bad. It’s a not terribly daring nor original sentiment that McKay nonetheless issues at a busy, self-satisfied blare, heralding the summative declaration we’ve long, he seems to assume, been waiting for.

Vice is a jumble of asides and visual gimmicks and pointed digressions, much in the same way that The Big Short was. That buckshot tactic worked well enough on something as diffuse and hard to gather as the complexities of Wall Street. But when applied to what could be called a biopic—a study of one person—all that antic reeling obfuscates more than it illuminates. There’s a title card at the beginning of the film saying that, though Cheney kept his life and deeds very hidden and private, McKay and company did the best they could to tell the real story. But that little caveat actually pries open a wide chasm of possibility, and badly blurs the line between fact and a filmmaker’s imagination.

What Vice can get concretely right is Cheney’s physical being. There’s plenty of that evidence on the record, at least. So enter Christian Bale, an actor who’s never been one to turn down a transformative challenge. Here he’s put on a considerable amount of weight, is wearing some kind of thin-pate wig, and has affected a sideways growl. He looks and sounds the part with eerie effectiveness. His Cheney is a mess of a young man who turns himself into a stealthy political operator, drawn to power and feeding off of it until he becomes his own formidable juggernaut.

In a vacuum, Bale’s performance would be a thrilling bit of imitation, a dark parlor trick that’s all the more exciting because no one else is doing it. But in Vice, Bale’s uncanny apery is leaned on too heavily, as if half the film’s work is done because it nails the Cheney impression. Successfully telling Cheney’s story—particularly how he was uniquely suited to leveraging loopholes in executive power to reorder U.S. security policy toward disaster—requires more legwork than merely a good impersonation. McKay set a difficult, exacting task before his movie, and yet he keeps it too hepped up on pieces of flair to really knuckle down and focus.

McKay has clearly seen a Michael Moore movie or two, and has certainly seen David O. Russell’s American Hustle. With Vice, he badly fuses those influences together. The film moves with unwieldy verve. It jumps back and forth between time periods for no narratively satisfying reason. It aims for both grave assessment and outlandish gags. McKay, who also wrote the script, pitches Cheney as an opportunist whose only ideology is . . . well, actually, I’m having trouble finishing that sentence, because I’m really not sure who McKay thinks Cheney is—what guides him beyond the empty, robotic drive the script instills in him. We hear a little about Halliburton, and see him learn lessons in political sneakiness from Donald Rumsfeld (Steve Carell). But there’s still a crucial why missing from McKay’s—and by extension Bale’s—portraiture.