Issac Bailey was the 2016 James K. Batten Professor of Public Policy at Davidson College. The opinions expressed in this commentary are those of the author. View more opinion articles on CNN.

(CNN) If, as Bob Woodward alleges and is being reported in early extracts of his tell-all book about the Trump White House, President Trump called his Attorney General Jeff Sessions, an Alabama resident, a "dumb Southerner," he may have finally done something he has long been unable to do: unite black and white Southerners.

We may not agree politically; actually, we disagree passionately on most issues. We don't see eye-to-eye on the issue of race and Confederate monuments and memorials. Even our views of Jesus and Christianity are diverging and increasingly at odds. But boy are we tired of having to contend with the stereotype that we are slow and unintelligent.

This side of the n-word, "dumb Southerner" is maybe the most impactful epithet you can throw at someone in the South. "Mentally retarded," another term Trump reportedly used to describe Sessions, is also high on the list. Trump has since tweeted a denial of using either term.

Calling Southerners some version of dumb is so effective that even Southerners do it to get under each other's skin.

Residents of South Carolina rejoice by thanking God they aren't Mississippians, who often show up at the bottom of good rankings and the top of bad ones , with South Carolina usually one rung above.

North Carolinians are proud to be home to the New South city Charlotte and the Research Triangle that includes high-profile universities, which makes it easier for the state to claim world-class status and deny that this stereotype applies to them, too.

Such slurs pick at an open scab, that of school districts in the South repeatedly showing up at the bottom of educational lists and too high on lists about heart disease. It is a scab that is reopened every time an A-list Hollywood actor speaks in a distorted, haunting drawl to try to sound genuine when portraying down-on-their-luck, unsophisticated Southern-based characters on the big screen.

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It stings us all, black and white. We are tired of having to remind people that we don't "talk different" any more than do Bostonians or Bronx residents, that the pace of the words that flow from our mouths is not indicative of the intellectual activity taking place inside our heads.

That's why even Trump ally Senator Johnny Isakson of Georgia, said "I resent that" when asked about Trump's use of the epithet.

A version of the slur was used in 2000 by a high-profile South Carolina state senator, Arthur Ravenel, for whom one of the longest cable-stayed bridges in North America is named, because the National Association of Colored People initiated an economic boycott of South Carolina to protest the flying of the Confederate flag at the Statehouse.

Ravenel caught heat for referring to the NAACP as the National Association of Retarded People -- then doubled down by apologizing to retarded people. He also later said he had mixed up his words because he was scheduled to meet with the SC Association for Retarded Citizens.

It was a way to put black Southerners in their place, to remind them that they would never be as good as white Southerners. Trump has turned even that racial divide on its head because he allegedly used the term to refer to a Trump-voting and supporting white evangelical Christian who served in the US Senate , was a captain in the US Army, received a law degree from the University of Alabama and is now the nation's top law enforcement official.

If Trump thinks that about a white Southerner with such a long list of credentials, there's little reason to believe he doesn't think the same thing about many of the white Southerners who always show up at his rallies to passionately praise and cheer him. What's worse is that the slur comes courtesy of a fast-talking New Yorker who never showed any concern for white Southerners, rich or poor, before he ran for president. And yet, I suspect, while black and white Southerners will be united in our outrage about the slur, many white Southerners will stick with Trump.

Just days after he announced his intentions to run for the presidency, I spent time reminding white members of the Tea Party in the Myrtle Beach, South Carolina, area that they had more in common with me, a black Southern native, than they did with Trump. Our parents and friends struggled to stay safe doing dangerous work at nearby factories and were struggling to find a new way forward as those factories were closing. We spent a lot of time praying for each other. We needed a better healthcare and more adequate educational system. We shopped, side-by-side, in Walmart and cashed our checks at local credit unions. We ate at the Southern-style buffet restaurants.

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Trump knew nothing about any of that, I said. It didn't matter. They flocked to him anyway, led by men like Sessions, the first sitting US senator to endorse Trump. That's why though I empathize with Sessions, and others like him who have to endure unfair slurs from men like Trump, I likely won't be shedding too many tears. I've been all cried out since the night of the 2016 presidential election.