"Global warming" is a dangerously loaded expression in the rural, Republican-loving, God-fearing Tennessee of Barbara Kingsolver's didactic and preachy new novel, "Flight Behavior." The people of the fictional Feathertown have been taught by talk radio that it's a big-city scam concocted by Al Gore.

But then shifting weather patterns bring millions of butterflies to the property of Dellarobia Turnbow's family. They're monarchs, the same ones that usually migrate to Mexico. Freaked out by warmer temperatures and a logging-induced flood that wiped out their Mexican habitat, they've turned north to spend winter in the America.

The appearance of the butterflies in the hills above Feathertown is a miracle, the local evangelical preacher says. Let's charge people to see them, Dellarobia's mother-in-law says. No, says Dellarobia's father-in-law: Let's kill them all with DDT!

Dellarobia, a stay-at-home mom with two young kids, is different - she took honors English at Feathertown High. Not only does it rile her that people in Feathertown end their sentences with prepositions, but she's also one of the small minority of enlightened people there who don't automatically distrust outsiders and scientists.

When a group of lepidopterists alights in Feathertown, Dellarobia learns the dark secret behind the appearance of those millions of feathery creatures.

"They said it means something's really gone wrong," she tells her husband, Cub.

"Wrong with what?" Cub asks.

"The whole earth, if you want to know," she says. "It's like the End of Days."

"Flight Behavior" has many of the trappings of a work of literary fiction. A strong female protagonist with a complicated recent past, for example, and extended, dreamy descriptions of a shifting natural landscape. But after just a chapter or two, the novel's true purpose becomes clear - it's a Blue State morality tale about Red State people and Red State thinking.

Kingsolver, who was raised in nearby Kentucky, spends much of the 400-plus pages of this book wagging her finger at poor white people. Dellarobia, whose dreams of leaving Feathertown to go to college were thwarted by a teen pregnancy, is her Blue State-thinking stand-in. She's trying to shake loose from the roots of her lethargic culture.

Kingsolver has built a reputation as a skilled novelist unafraid to tackle issues of inequality and cultural conflict. With "Flight Behavior," however, Kingsolver appears to be turning her back on serious literary aspirations. The writing is often turgid and peppered with mixed metaphors and sloppy similes. "The heels of her oxblood boots struck the waxed floor loudly," Kingsolver writes when Dellarobia enters a church, "advertising her traveling whereabouts like a GPS."

More than anything, it's the not-subtle condescension of "Flight Behavior" that strips the work of artistic weight. Consider Kingsolver's description of a local named Dimmit Slaughter, who rides up on his Harley to look at the butterflies: "his T-shirt stretched to within an inch of its life across his broad belly, where the letters distorted outward like horror movie credits."

Kingsolver does give us a back story about Dellarobia's marriage to Cub that has enough moments of emotional insight to suggest we're reading a thoughtful novel, and not an environmentalist parable. But every time this domestic drama gets going, the moralizing quickly works its way back in, especially after Dellarobia joins up with the scientists as a field assistant.

In the end, Dellarobia has to decide whether a smart, nature-loving woman can live among the unenlightened and stay true to herself. Given the portrayal of Appalachia in "Flight Behavior," few readers would blame Dellarobia if she just decided to pack it all up and run away.