Philip Roth has built his bold but vexing 26th book, The Plot Against America, around a daredevil premise: It's 1940 and anti-Semitic Charles Lindbergh ''a goyisch idiot flying a stupid plane'' unseats President Franklin D. Roosevelt. And so, instead of joining the war against Hitler in 1941, the United States signs a peace pact with Nazi Germany. The working-class Roth family of Newark with precocious 7-year-old Philip narrating begins experiencing a monstrous new America drunk on ''the intoxicant of anti-Semitism.'' This could conceivably have happened, Roth has asserted, if the Republicans had chosen the handsome, popular aviator as their candidate.
Maybe, maybe not. But with this fascinating, fertile material, Roth has spun an unconvincing fantasy that falls far short of his finest work. While his depictions of the Roth family's idyllic pre-Lindbergh existence (and Philip's vibrant, eccentric inner life) are detailed and persuasive, he has set them against a cardboard backdrop of a fatally underimagined alternative America.
As Plot begins its leisurely, episodic unfolding, our lively, inventive young narrator, an avid stamp collector, lives with his saintly mother, Bess, his upstanding father, Herman, and his revered older brother, Sandy. They inhabit an insular working-class American paradise that Roth evokes with unabashed nostalgia: an all-Jewish neighborhood where the children play safely on the streets, the hardworking men take up pinochle in the evening, and the women cook, clean, and worry.
They have plenty of reason to worry after Lindbergh unexpectedly wins the White House. Herman, a staunch patriot and the book's outspoken, eminently likable hero, detests the new president but insists that his family proceed with a long-planned trip to Washington, D.C. As they tour the monuments, brutish anti-Semites pop up at every turn like zombies in a cheap amusement park ride, hissing ''loudmouth Jew'' at the slightest provocation.
The hallucinatory Washington scenes cast an eerie spell, but they shatter the fragile illusion that what you're reading could possibly be true. These stereotypical B-movie bigots are easy to loathe but they're painted with a far coarser brush than the one Roth has used to portray his family, and the contrast is jarring.
After the Roths return to Newark, the encroachments on their freedoms come gradually in the form of insidious government programs with hilariously cheery names. Adolescent Sandy is sent to Kentucky (which takes a real drubbing in this novel) with the ''Just Folks'' initiative, to pull weeds on a tobacco farm and commune with gentile Americans. He returns home talking like a hick, stuffed with bacon, and alienated from his ''ghetto Jew'' parents.
This is dark, funny stuff, but Roth offers no analysis of Sandy's bizarre conversion, let alone the mindset of the hayseeds with whom he's been so cheerily milking cows. You get little sense of the connective tissue between the sympathetic central characters and the purportedly venomous society poised to do them in.
The novel's end brings an absurd, abrupt denouement to the crisis, though not before a Kentucky pogrom leaves 122 Jews dead, including a neighbor of the Roths' who the Lindbergh government relocated there. To rescue her orphaned son, Herman makes an epic 1,500-mile drive (''his Battle of the Bulge'') through a wasteland of shanties, saloons, pickup trucks, and ''upright American Christians unleashed.'' That's a sweet, heroic mission to imagine for a beloved father, but to turn a huge chunk of America into proto-Nazis required more time, effort, and artistry than Roth put into his fleeting, hammy snapshots.