To fully appreciate Tom Perrotta’s ’83 latest novel, “The Abstinence Teacher,” it helps to imagine that it is October 2004 again, in the final weeks of the presidential election. George W. Bush is headed for re-election, thanks in large part to the overwhelming support of the religious right and the machinations of Karl Rove. Constitutional amendments banning gay marriage are on the ballot in several states, and a Republican movie star has even managed to capture the governorship of that greatest of liberal bastions, California.

Against that backdrop, the conflict at the center of Perrotta’s novel — between a divorced sex-ed teacher who puts condoms on the list of “Public Health Marvels of the Modern World” and a recently born-again ex-Deadhead — feels like it might just be enough to drive a 358-page novel.

But in 2007, without a Republican presidential candidate who can lay claim to the evangelical vote, the political star of the Christian right appears to be on the wane. So despite a cast of beautifully crafted, fully human characters, “The Abstinence Teacher” falls a bit flat, never achieving the climax the reader is waiting for up to the very last page.

The novel begins with Ruth Ramsey — the aforementioned sex-ed teacher — heading off to her first day teaching a new abstinence-only curriculum. The new script is Ruth’s punishment for telling her students the previous year that some people like oral sex — that it is not, in fact, like “French-kissing a toilet seat.”

A few days later, already enraged by the new, “Virginity Consultant”-approved curriculum, Ruth watches her daughter’s soccer coach lead the team in a prayer circle following their win. Perhaps rightly, Ruth sees the prayer as just one more sign that her town is being taken over by the evangelical members of the new Tabernacle church.

The soccer coach, Tim Mason, is one of the Tabernacle “Bible thumpers,” but what Ruth doesn’t know is that the church was his ticket out of drug addiction and unemployment. The former rock musician had one failed marriage and a daughter he barely knew when he found Pastor Dennis and the Tabernacle; now, he coaches his daughter’s soccer team and is remarried to a good — and much younger — Christian girl.

Ruth is dismayed by the team prayer, but she succumbs to a frisson of sexual tension with the coach and abandons her planned letter-writing campaign. Meanwhile, Tim’s attraction to Ruth fuels his doubts about his faith, his marriage and his ability to resist the siren call of drugs and alcohol. He never meant to ignite a fight over religion’s place on the soccer field, and when his pastor encourages other Tabernacle members to sign up to coach Little League or Pop Warner or youth soccer just so they too can lead team prayer, Tim becomes even more uncomfortable.

So the clash of the suburban titans — snarky atheist versus sanctimonious churchgoer — never quite materializes, and we are left with a pair of character studies of suburbanites who don’t quite fit into their precious New Jersey town.

Like Perrotta’s previous novel “Little Children,” “The Abstinence Teacher” is told from the viewpoints of the two main characters. The earlier novel, also set in contemporary American suburbia, focuses on Sarah and Todd, unhappy stay-at-home parents whose impromptu playground kiss sparks a torrid affair. Perrotta has refined the structure in “The Abstinence Teacher,” eliminating occasional digressions into the perspectives of a few minor characters.

In one way, this tight structure works beautifully. “The Abstinence Teacher” is a realist novel — Perrotta attended an evangelical conference, studied up on the mortgage industry and read the Bible daily as part of his research for the book — and his characters are both utterly believable and a pleasure to spend time with on the page. He is able to depict Ruth’s struggles with her job, her just-teenage daughter and her newfound singledom without condescension. And as he did to great effect in “Joe College,” Perrotta again demonstrates a keen insight into the adolescent mind when he recounts Ruth’s unromantic deflowering at the hands of a neighbor boy.

But the dual structure is naturally conducive to a collision between the two characters. In “Little Children,” Sarah and Todd began the novel as strangers but were quickly drawn into an affair. In “The Abstinence Teacher,” Ruth and Tim begin the novel as strangers, but the drama suggested by their initial flash of connection is left unresolved. Plenty happens in the meantime, but you’ll still turn the final page with a nagging expectation of more to come.