Nikki Haley made one of the few real blunders of the GOP primary season when she was asked at a New Hampshire town hall, “What was the cause of the United States Civil War?” For a Republican, this shouldn’t be a tough question. The Republican Party was founded mostly to oppose slavery. But Haley equivocated, in rather weird fashion:

The cause of the deadliest conflict in American history, she said, was “basically how government was gonna run—the freedoms and what people could and couldn’t do.”

She went on: “We need to make sure that we do all things so that individuals have the liberties so that they can have freedom of speech, freedom of religion, freedom to do or be anything they want to be without government getting in the way.”

That would be a more plausible explanation of the causes of the Revolutionary War than the Civil War. To talk about the origins of the Civil War without mentioning slavery–when someone in the audience followed up, Haley responded, “What do you want me to say about slavery?”–seems inexplicable, especially to us northerners.

Haley’s bad moment may simply indicate that she isn’t as good on the stump, as quick on her feet, as she needs to be. Maybe that is all there is to it. But I suspect there is another element: a longstanding Southern conviction, in many quarters, that the War Between the States was not about slavery.

Most northerners are not tuned into this, but that theme persists in the South. One of my brothers lives in North Carolina, and some years ago he told me about an encounter with an employee at his local post office. He was mailing someone a book on the Civil War, and got into a conversation about it with the postal employee. “Well you know,” she said confidentially, “that war wasn’t about slavery.” That attitude may be delusional, but it isn’t hard to understand why many southerners, steeped in regional history, prefer to adopt it.

So maybe Nikki Haley is just inept on the stump. But she isn’t randomly inept. She grew up in South Carolina and served as governor of that state. She is well acquainted with the nuances of belief in the southern states. And I suspect that even today, she saw it as problematic to assert unreservedly that slavery was the cause of the Civil War. If so, it was a serious misjudgment–certainly in New Hampshire!–and it does cast reasonable doubt on Haley’s strength as a presidential candidate.