There was an awful lot to unpack in the letter to the editor that leaped from the pages of South Carolina’s Spartanburg Herald-Journal one day last month. Writer Winston McCuen touched upon “Marxist mobs,” statue-toppling, “cloistered professors” and the political philosophy of Andrew Jackson’s vice president, John C. Calhoun.

But one of his arguments came through loud and clear. When it came to slavery, McCuen declared, Calhoun and the Confederacy were dead right.

“God rewards goodness and intelligence; and that slavery is how He justly punishes ignorance, sloth and depravity,” he wrote.

Herald-Journal readers were appalled: Spartanburg is a city that had just dedicated a Black Lives Matter mural and joined a national alliance to address racial inequities. The executive editor raced out with an apology. The “racist and repugnant” letter, Steve Bruss wrote, “caused pain in our community” and never should have made it into print.

From the cacophony of Facebook and Twitter to the rarefied pages of the nation’s most elite opinion digests, debates have been raging this summer about how forums devoted to an exchange of ideas should deal with incendiary topics and toxic words. But it’s an issue that regular old local newspapers have been grappling with for decades — through the quaint but vital institution of the letters-to-the-editor page.

Letters let readers weigh in on coverage or sound off on newsy issues. They also give publications a way to print opinions that differ from the rest of the newspaper’s content. And between the coronavirus pandemic and protests sparked by the deaths of unarmed black people at the hands of police, letters have been fiery lately — triggering controversies for several newspapers.

“We’re in a divisive moment,” said Kevin Walter, the editorial page editor at the Buffalo News. “You just can’t ignore that. It doesn’t trouble me if it comes across in the passion of the writers, but there’s got to be some line where you say, this is too far.”

In Cayuga County, N.Y., the Auburn Citizen printed a letter from a GOP legislator that began with the declaration, “I’m sure after this letter I’ll be called a racist but that’s fine because I know I’m not.” Andrew Dennison went on to call racism “a two-way street,” referred to critics of Confederate monuments as “idiots” and blamed protesters for the deaths of black children.

Lawmakers from both parties condemned the letter, while the Citizen’s pages filled up with numerous letters of rebuttal. He eventually resigned as chairman of the county public safety committee.

Some editors have also noted an uptick in name-calling and vitriol in their online comments.

“Among the many things that make community newspapers special is their ability to serve as a public forum,” Bubba Brown, editor of the Park Record of Park City, Utah, wrote in a recent column. But he pleaded with readers to please be more civil in comments on stories on the paper’s website and Facebook page. “The situation has worsened and tensions have become even more inflamed. . . .”

Things have gotten so bad for the Orlando Weekly that it recently killed its comments feature. Editor in chief Jessica Bryce Young has instead encouraged readers to go old school and submit letters for print, which allows newspapers to make editorial judgments about what to publish.

Reader letters have “an interesting interaction with gatekeeping — who gets to say what’s important enough to cover — and those are all different aspects of the same story that the culture is working out right now,” Young said.

While she’s not looking to “amplify abuse or hatred,” Young likes to juxtapose “really radically different viewpoints in the letters.” It’s all too easy for alt-weekly readers in a liberal-leaning town to remain in their “progressive bubble,” she says, so “it’s important to see that not everybody thinks the same way they do.”

Although publication of an opinion doesn’t equal its endorsement, newspapers bear responsibility for the content of their letters in a way social media platforms don’t. They can be sued if readers’ letters contain libelous material. Many editors say they forbid personal attacks, name-calling and overt hate speech.

Still, the lines can be murky — and when some readers push them, others will push back. Last month, the Island Now paper of Nassau County, N.Y., published a letter from a reader who described racial justice protesters as “Marxist-inspired radicals – Antifa and Black Lives Matters” running a “professionally orchestrated, bountifully financed rampage” of America’s cities and suburbs. Another upset reader responded with his own letter, taking aim not just at the original letter-writer but the paper, arguing that such opinions “validated by publication, only stoke discord and further erode our already vulnerable democracy.”

Island Now publisher Steven Blank defends the “Readers Write” section as a way to inform readers about what their neighbors think, “even if it’s extreme” — and that’s different, he says, than giving a platform to dangerous ideas without challenge.

“In a perfect world, you have people who will respond and counter those ideas,” he said. “We know those ideas are out there. It’s not that we’re introducing something into the body politic. These are prejudices that have been there forever.”

His approach has caused him grief before. Blank published a letter following the 2016 election from a Trump supporter that referred to anti-Semitic conspiracy theories. He initially defended his decision to run the letter, citing Trump campaign commercials that made similar allusions, but then apologized following a boycott threat, saying he recognized “the exceeding sensitivity in the community to this.” (The area is home to Holocaust survivors and descendants).

But the job of making the decisions about when a letter goes too far over the line has gotten more difficult for some local newspapers, especially those dealing with budget cuts and shrinking staff.

“The system we had in place for vetting letters before publication failed,” Bruss wrote in his editor’s note about the proslavery letter that ended up in the Spartanburg Herald-Journal. “That system is being changed to ensure that a local editor approves every letter we publish and to add a layer of accountability.” (Bruss declined to elaborate in an email to The Washington Post).

As it happens, McCuen is a prolific correspondent who has placed dozens of letters in newspapers throughout South Carolina — including ones that veered into anti-Semitic territory, defended racial segregation and cast miscegenation as anti-Christian and responsible for the downfall of America. (He’s made headlines in the past as a teacher fired after his protest over being forced to remove the Confederate battle flag from his classroom.) McCuen did not return a call for comment.

In 2017, the State of Columbia, S.C., published a letter in which he praised Calhoun’s views on “Christian slavery” and referred to “oppressive racial integration.” Later, editor Cindi Ross Scoppe wrote an editorial explaining why she published a letter from an “unapologetic white supremacist.” It was, she said, “an extreme version of what we do five days a week: provide a public forum where we hold a mirror up to our community, so it can examine itself, warts and all.”

She wrote that she knew the letter would get a backlash; she was glad that most readers’ ire was aimed at the writer, and she hoped everyone learned from it.

“The sad truth is that you don’t have to look hard to find South Carolinians who believe that slavery was good because, in their view, black people are inherently inferior to white people. They even feel comfortable attaching their names to their warped views.”

“And,” she added, “I believe all South Carolinians need to know that.”