In his 1998 non-fiction classic, Confederates In The Attic, Tony Horwitz explored the world of the American Civil War reenactment, the slightly disreputable preserve of enthusiasts who prefer a more participatory element to their appreciation of history.

Horwitz's even-handed and generous approach was a way of plumbing the depths of the Civil War's cultural legacy and identifying its residual traces in the popular imagination.

If Horwitz was scrupulously objective in his journalism, the four UC Berkeley students in T Geronimo Johnson's second novel have more polemical motives in mind when they arrive in the eponymous Georgia town, intent on disrupting its annual reenactment. Stuffed with critical theory and an overwhelming sense of self-righteousness, Candice, Louis, Charlie and Daron plan to stage a fake lynching and record the reactions, a "performative intervention" that will expose the racist roots of the town's commemorations and shine a brighter light on a still largely unreconstructed South. It's no accident, they think, that the Braggsville reenactments started in 1956, the same year the state legislature voted to end school segregation.

In aggregate, the students are the best example of America's melting-pot philosophy, and a ruthless contrast to the de facto segregated town. Louis, a Malaysian-American, is an aspiring stand-up comedian who styles himself 'Lenny Bruce Lee', while Charlie is a young black man struggling with his sexuality, who has more than most to fear about his reception in the Deep South. Candice is a privileged white girl from Iowa, already a veteran of racial politics after protesting against UC Berkeley's historical treatment of Ishi, the last of a native American tribe who was forced into becoming a living anthropology exhibit. Finally, Daron (who has changed his name from the more redneck-sounding D'aron), is a Braggsville native, an overachiever glad to escape his home town even as he harbours a grudging respect for the community that raised him.

Braggsville is an uneasy mix of deep if unthinking prejudice, and genuine openness and hospitality. Although Daron has to remind his uncle not to use the word 'nigger' and the local gas station sells openly racist bumper stickers ("If I'd known it would be like this, I would have picked my own cotton"), the students are still met with politeness and grace; on the surface, the town seems nothing like their Deliverance-style preconceptions. When the fake lynching goes horribly wrong , however, and as the inevitable media circus descends, they find that their defence of 'irony' and invocation of theorists like Judith Butler cut little ice with the authorities. Daron in particular is forced to confront the murky roots of his own potential bigotry, and the realisation that his home town might be more sinister than he thought.

Johnson writes in a free-wheeling, hyperbolic prose in the postmodern lineage of Thomas Pynchon and David Foster Wallace, but on a sentence by sentence level this straining for contemporaneity soon starts to grate. The page-long footnotes, the fussily rearranged clauses, the chapter numbers uneasily and unnecessarily rendered as, for example, 'Twenty-1, Twenty-2' and so on, merely detract from what can at times be a sharp way with observation and simile: "A single slice of ham," he writes, "fainted across the wax paper like a Southern belle in sight of a chaise longue."

The real problem with the novel is structural. The first third is a vicious and uncompromising satire that ruthlessly attacks the hypocrisies of the US's attitudes towards race, and the self-indulgence of the politically correct who can obsess over minor racial slights but have no authentic response to genuine racism when they encounter it. Culminating in the disastrous fake lynching, this part of the book feels urgent and necessary.

Once over, though, the rest of the novel meanders in search of a conclusion that in many ways it has already reached. The fall-out from the lynching, the police interviews and the dark hints of a local militia pulling the strings, are almost subsumed by Daron's heartsick yearning for Candice and by his melancholy realisation that he is now permanently estranged from the place where he grew up. No amount of postmodern narrative horseplay can disguise the imbalance here; 15 pages of Daron's fictionalised thesis, Residual Affect: Race, Micro-aggression, Micro-inequities (Autophagy) & BBQ In Contemporary Southern Imagination At Six Flags, is no substitute for a book that can identify its targets and hit them full force, and the weaknesses here go some way towards blunting that earlier satire.

As much as for its subject matter as for its linguistic verve and exuberance, this is certainly a book worth reading.It could so easily have been a great book, if Johnson, who is a skilled and vigorous writer, had been less enamoured of his characters and more focused on his transgressive ideas.