No one does raging unlovability quite like John Malkovich, who’s a total gas when he drops the bombast that often bogs down his more serious roles. Not that Buck Howard, the once-great mentalist now playing to half-empty theaters in Hicksville, lacks for pathos-or for glory. His lounge act is excruciating, his stand-up terrible, but his one gift, locating his paycheck in the clothing of an audience member, has never let him down-until now, it goes without saying. Based on a magician known to writer-director Sean McGinly, this loudly dressed, insecure blowhard with a pumping handshake and severe anger management problems may also be an ambivalent tribute to Jerry Lewis. Either way, Malkovich swallows up the screen, and when he’s out of frame, the movie feels slack and slow. Hobbled by lack of definition, Buck’s assistant and McGinly’s alter ego, Troy (Colin Hanks), a law school dropout with dreams of writing, comes across as pallid and passionless, while the talents of Emily Blunt as a go-getting publicist and Steve Zahn as a small-town fan go wretchedly to waste. But though it laments our decaying faith in magic and mystery, The Great Buck Howard is rarely mawkish. McGinly sheds no tears for this clown, and he makes a beguiling case for following your bliss all the way to Bakersfield, if that’s where it lies.