The gloomy Wyeths -- N.C., Andrew and Jamie, grandfather, father and son -- are the painters laureate of American upper-middle-class WASPs and those who take their style from them. This is the class that leftists used to call the American bourgeois, a tribe that sees itself, and rightly so, as a casualty of the 20th century.

The affection of these people is one reason the Wyeths, particularly Andrew and Jamie, get attacked by modernists. These attacks have been going on for decades, and the big show that opens tomorrow at the Corcoran Gallery -- "An American Vision: Three Generations of Wyeth Art" -- will do nothing to end them.

In 1953, just as Andrew Wyeth's star was being installed in the firmament, a critic wrote in Art News that " 'nice people' can be at ease with his pictures." Critic Jay Jacobs once called Andrew Wyeth "the spiritual leader of Middle America." Carter Ratcliff wrote in Art in America that "those committed to modernism hold Wyeth in contempt of art. Others gauge their contempt for modernism by their love of Wyeth."

The Wyeths' audience looks to Britain and a lost rural past for its identity, while the modernists look to cities and the Continent. The Wyeths defend the work ethic -- N.C. could crank out his masterful illustrations one a day; Andrew appears to paint each blade of grass; Jamie records every strand of wicker in the antique wheelchair that holds a woman staring out to sea. They've all made lots of money. They arouse emotions that happily require no moral choices -- poignance, wistfulness, nostalgia, depression, self-awareness, satisfaction. They meld those emotions with puritanical vigor and stoic spareness. And they defend the sort of 19th-century sensibility that found thrilling meaning in death, moral character, the struggles of nature, production and solitude -- as opposed to the modern sensibility that admires nihilism, personality, the benevolence of nature, consumption and the masses.

The Wyeths stand for their audience's nobility in the face of the quiet calamity of the 20th century -- these people have been losing political power and moral sway ever since the tidal waves of turn-of-the-century immigration, the progressive income tax, the stock market crash of 1929 and the egalitarianism and meritocracy that came out of World War II. In John Cheever's "The Day the Pig Fell Into the Well," a mother looks at her family and asks herself: "Where had they lost their competence, their freedom, their greatness? Why should these good and gentle people who surrounded her seem like the figures in a tragedy?"

This decline has been a major theme in 20th-century American culture, but art has ignored it, except for the Wyeths. F. Scott Fitzgerald turned it into an ur-myth with "The Great Gatsby." The New Yorker magazine's tone of wistful perseverance, along with all those memoirs of childhood, depends on it. The best gods, it seemed, were dying ones. Nostalgia became a virtue. Irony became the preferred tone, as in Ernest Hemingway or J.D. Salinger.

To be upper-middle-class in 20th-century America means not just living with a sense of loss but reveling in it, flaunting it, laying claim to an ancien re'gime. This nostalgia has gone from esthetics to a merchandising bonanza, resonating through everything from the Anglophilia on public television to the hundreds of dollars that people will spend on a single antique duck decoy. (Once the lion was the totem animal of the ruling class; now it's the duck. A duck's head even appears on the front of a limousine in one of Jamie Wyeth's most sentimental paintings, "New Year's Calling." And is that Jamie himself staring out of the back window?) The WASPs are acquiring the poignance of a lost tribe -- college kids wear WASP, or preppy, clothes today the way they wore Navajo beads and Sioux moccasins in the 1960s.

And now we have two big Wyeth shows in Washington at the same time -- the Helga show by Andrew Wyeth at the National Gallery and the one at the Corcoran, sponsored by AT&T. Even with the $3 admission for adults, the Corcoran show, which was recently on view in the Soviet Union, is likely to draw big crowds before it closes at the end of August.

It's useless to speculate on the Wyeths' esthetic and technical merits. This line of criticism examines them as either realists or abstractionists, and as it happens their skills as either are not remarkable in the history of art. Where their particular genius lies is in their ability to evoke emotions, the sort of emotions that appeal to psyches that few other painters have taken seriously.

Early in this century, as he was beginning to illustrate muscular Anglo-Saxon adventures such as "Robin Hood" and "Treasure Island," N.C. Wyeth wrote: "Anything that I appreciate keenly and profoundly is always sad to the point of being tragic. Whether it is a lone tree on a hillside bathed in the fading light of the afternoon sun, or the broad stretch of a green meadow shining and sparkling after a shower ... it is all so sad, because it is all so beautiful, so hopeless."

His son Andrew was born in 1917, just as the Anglo-Saxon adventure was ending in the horrible ironies of the trenches in World War I. Instead of painting knights, pirates and cowboys murdering each other with jut-jawed abandon, Andrew has given us pictures of dry, mysterious moments in a vanishing rural landscape where hair glitters in the wind and snow blows over the hills with the glamor of some unspoken aftermath.

Andrew says: "I prefer winter and fall, when you feel the bone structure in the landscape -- the loneliness of it -- the dead feeling of winter. Something waits beneath it -- the whole story doesn't show." He summers in Maine, which gives "the impression sometimes of crackling skeletons rattling in the attic ... I feel things are just hanging on the surface and that it's all going to blow away." He likes painting with egg tempera because "it has a cocoon-like feeling of dry lostness -- almost a lonely feeling."

James, called Jamie, was born in 1946. He evokes his brand of gloom with irony -- a preposterously noble ram in the slanting sunlight, himself with a pumpkin on his head, a huge pig (emblematic of the horrible vigor of nature) trotting in one direction while a locomotive (emblematic of the horrible vigor of the 20th century) steams in the other. As he says of Monhegan Island in Maine: "Fall, you know, that's the great time. There's a wonderful sort of melancholy. Nobody's here. Houses are closed up, sheets are pulled over furniture. I love it."

The Wyeths have given gloom, romance, morbidity and lurid wistfulness the stature of eternal truths.

The catalogue of the Corcoran show begins with a genealogy. Nicholas Wyeth came from England to Cambridge, Mass., in 1645, Wyeths died in the French and Indian War, and so on. It's hard to imagine a catalogue of, say, Andy Warhol or Helen Frankenthaler paintings beginning with a genealogy, especially of ancestors with no particular distinction, but with the Wyeths it seems appropriate.

N.C., Newell Convers, was born on a farm in Needham, Mass., in 1882 and studied art near home. In 1902, the golden age of illustration, he went to Wilmington, Del., to study with the dean of American illustrators, Howard Pyle, who exemplified the vitalist movement of the time: "We of today are not children, but men, each of us with a man's work to do." He must have loved seeing N.C., the huge farm boy, come through the door. In 1904, having decided to paint "true, solid American subjects -- nothing foreign about them," N.C. went out west to study cowboys and Indians, whom he then painted in countless illustrations that began his career.

He never settled on a single style -- his palette brightened and dimmed, edges hardened and blurred, paint thickened and thinned. But he threw the paint around with masterful gestures. Where his son and grandson seem to tiptoe up to the canvas in dread, N.C. has a fine old time getting horses to gallop wild-eyed at us, Civil War artillerymen to struggle through the mud.

Unlike Andrew and Jamie, who have had to fight off charges that they are illustrators, N.C. had no choice but to embrace illustration, and in so doing seemed to free himself to indulge the range of his skills. In "Robin Hood and His Companions Lend Aid," the focus of the picture is archers drawing their bows in Sherwood Forest, but the pleasure of it lies in the huge foreground of grass, which N.C. paints not just in greens, but in salmon, blue, yellow and orange. What amazing energy there is in that gout of paint he wallops onto the sunlit shirt in "At the Cards in Cluny's Cage," and in the blaze of brush strokes that fling a parrot into the cage in "Long John Silver and Hawkins." Surrounding the figure called "Winter," who stands in a windblown cape, is a battery of rhythmical brush strokes that seem like a splurge of van Gogh.

There's a grimness to all this vigor, though. The light blazes but the shadows lurk, and N.C. reflects the yearning for lost ages that was paired with future-mania in the boys' literature of his time. To our eyes his paintings also have acquired the glow of the toys from our parents' and grandparents' childhoods. In what may be his most famous painting, "Old Pew," the satanic blind messenger of "Treasure Island" flails his way through the brilliant moonlight outside a Benbow Inn modeled on the house of N.C.'s childhood. It has the power of a monstrous cri de coeur. When he was killed in 1945 by a train in Chadds Ford, Pa., he was a man who mourned his failure to be more than an illustrator. He wrote in a letter: "All sense of serenity and security has crumbled away and all I can do, when I think about it all, is to gawk stupidly at the retreating pageant of my dreams and hopes."

He had lived in Chadds Ford since early in the century. "This is a country full of restraints," he wrote then. "Everything lies in its subtleties, everything is so gentle and simple, so unaffected."

Andrew would turn this gentility into a genre. His landscapes, according to Lincoln Kirsten, the ballet promoter and a family friend, have "affirmed a nostalgic Eden of preindustrial stoic innocence." But so did the paintings of Grandma Moses, who seemed to be the Wyeths' only rival as America's Artist in the Time and Life magazines of a generation ago.

Andrew's knack is showing this Eden just as the storm clouds gather. Unlike 18th- and 19th-century artists who dwelled on ruins, Andrew loves to paint the moment when the weeds and the wind are just beginning to pull the stones apart. In "Lovers," one of the Helga nudes, a naked woman sits by an open window while a dead leaf blows past her thigh. Wyeth likes to place an ominous little flick of white at the top of a painting -- foam in "Adrift," snow in "Spring" and rocks in "Indian Summer." It lurks, it threatens. His tire tracks in "Spring" or "Border Patrol" show that the 20th century has been here and nothing will ever be the same.

Of course, he could have appealed to the same audience either by assuring them, like Norman Rockwell, that the nightmare wasn't happening, or by painting hokey WASPery like the blessing of the hounds. But he went that sort of thing one better -- he confirms decay, and then finds nobility in it. He catches a dour northernness and finds beauty in our Protestant fear that we do not deserve our blessings and are doomed by them, somehow.

In "Siri," a gloriously attractive tempera, the innocence of the young blond girl is so conspicuous that it insists on the inevitability of corruption. Behind her, the spirit of Jonathan Edwards and the Puritans watches from the shadows on the white colonial woodwork. Her hair snags the light, in the manner of those morbid little flicks of white that Wyeth likes, and the light is fading.

Everything seems like a symbol in an Andrew Wyeth painting. To some people this points to ulterior motive and corniness, but others are grateful that Wyeth puts meaning into the world. It's an odd sort of meaning, though, and it has little to do with the subjects he paints. Charles Burchfield and Thomas Hart Benton were American realists who dealt, like Wyeth, with common and rural subjects. In their paintings shapes whirl and curve with an animal spirit, as if the whole world is alive and has a soul. The spirits in Wyeth's world are ghosts, wistful harpies whirling over the hills in the guise of snow flurries.

He says: "I have such a strong romantic fantasy about things ... You look at my pictures ... there's witchcraft and hidden meaning there. Halloween and all that is strangely tied into them."

Where Andrew paints the spirit of Halloween, his son Jamie paints jack-o'-lanterns and leaves it at that. He doesn't create nostalgia, gloom or poignance as much as he gives us totems of them and hopes we'll do the rest with our imaginations, the way Ralph Lauren hopes to inspire thoughts of bygone aristocracy by selling us shirts with polo ponies embroidered on them. Like his grandfather, Jamie paints in oil, and he can't seem to find a style that's comfortable for him. Unlike N.C. he can't surrender to his subjects or his material. He shares with his father a need to dominate everything before him, and the urge to play to that most desired of upper-middle-class attributes -- self-consciousness. He also tends toward kitsch, as in the blond woman driving two white horses and a buggy into the ferny forest in the ridiculous "And Then Into the Deep Gorge."

There's considerable irony in many of these paintings, as in the duck's head on the hood of the limousine. He returns to the brutal grandeur of the Anglo-Saxon themes his grandfather illustrated, but he finds the grandeur in animals -- black angus, geese, sheep, pigs. For that subset of WASPdom that measures its humanity by the depth of its love for animals, this will be gratifying. There's also the irony of a painter with his skills -- as in "Night Chickens" -- and clout -- as in the commissioned portrait of John F. Kennedy -- addressing such trivial subjects. These paintings look like the kind of thing a young, uncertain man might paint to impress his mother's rich friends.

Even if Jamie didn't paint, he'd have stature as a Wyeth, a family credited with keeping the flame of a particular sensibility. If art is a religion, the Wyeths are somewhere between parish priests and druids. And the metaphysical divines of the more cosmopolitan art world will continue to hold them and their admirers in contempt.