Friday morning, America’s great poets will wake up to find that someone has TP-ed their trees and scrawled “COWARD” on the door.

A 6,000-word jeremiad about the pathetic state of contemporary poetry appears in the July issue of Harper’s magazine, which hits bookstores Friday. In “Poetry Slam, or, The Decline of American Verse,” Mark Edmundson, an English professor at the University of Virginia, upbraids our bards for being “oblique, equivocal, painfully self-questioning . . . timid, small, in retreat . . . ever more private, idiosyncratic, and withdrawn.” That’s just for starters.

“Their poetry is not heard but overheard,” he laments, “and sometimes is too hermetic even to overhear with anything like comprehension.”

And he names the names. After studying Paul Muldoon for years, Edmundson complains that he still has “barely a clue as to what Muldoon is going on about.” Jorie Graham is “portentous.” Anne Carson may be Canadian, but that’s no defense; her verse “is so obscure, mannered, and private that one (this one, at least) cannot follow its windings.” John Ashbery “says little” in his “perpetual hedging.”

“One can’t generalize about it all,” Edmundson warns, before generalizing about it all in a nuclear assault that leaves no poet standing.

Sharon Olds, Mary Oliver, Charles Simic, Frank Bidart, Robert Hass, Robert Pinsky — they’re all brought into Edmundson’s office for a dressing down. Their poems “are good in their ways,” he concedes. “They simply aren’t good enough. They don’t slake a reader’s thirst for meanings that pass beyond the experience of the individual poet and light up the world we hold in common.”

That is Edmundson’s central complaint: Our poets today are too timid to say, “‘we,’ to go plural and try to strike a major note . . .  on any fundamental truth of human experience.” Unimpressed by or unaware of any poets who might contradict his blanket condemnations, he claims that in the face of war, environmental destruction and economic collapse, “they write as though the great public crises were over and the most pressing business we had were self-cultivation and the fending off of boredom.” All that matters to these narcissistic singers is the creation of a “unique voice.”

Wouldn’t you know it: The old hobgoblins are to blame for this failure. MFA programs force brave young students to stoop and shuffle to please their worn out masters. “You must play the game that is there to be played,” Edmundson writes. To get the fellowship, the first book, the teaching job, the new poet “had best play it safe, offend none.”

And then, naturally, there’s the toxic effect of literary theorists working right “down the hall from the poets.” With their insistence on the impermeable barriers of race, gender and class, these liberal post-modernists keep anyone from saying anything about anything but his own private world. “How dare a white male poet speak for anyone but himself. . . . How can he raise his voice above a self-subverting whisper?”

Could this essay in Harper’s spark a real literary wrestling match? Possibly, although poets are pretty inured to these well-worn grievances. Edmundson admits early on that Ralph Waldo Emerson preached essentially the same complaint 170 years ago. The very best result might be some illuminating essays on all the politically and socially courageous poets who are, in fact, publishing today. Edmundson’s careful omissions make that a fairly easy list to compile, starting with our newly reappointed poet laureate, Natasha Trethewey.