Let’s not get carried away here, friends told me yesterday. A flag is just a symbol. When they stop passing voter-ID laws or start passing gun laws, then I’ll be impressed.

This is a sound view, no doubt about that. But if you don’t think symbols matter, think about how tenaciously people fight to hold on to them. And more than that: In terms of our political culture, the pending removal of the Confederate battle flag from South Carolina’s capitol grounds, and now Mississippi’s state flag—and, don’t forget, from WalMart’s shelves—represents a rare win for North over South since Reconstruction.

This is a history and set of facts that far too few Americans know, and it’s vitally important to understand it in order to grasp the full magnitude of this moment. The South, more than the North, has dominated and defined the limits of America’s political culture for most of the last 140-ish years. The North has the money, the North has Wall Street, and the North runs (most of) our high and popular culture. But the South has run our politics. And this moment that we’re witness to now could be the blessed beginning of the end of all that.

It all started during Reconstruction, when a debate ensued about how the Civil War would be remembered. Our guide through these waters is Yale historian David Blight, whose groundbreaking book Race and Reunion tells this story. He shows masterfully how collectively historical memory is constructed.

According to Blight, there were three competing interpretations of the war. The “emancipationist” one emphasized slavery as the cause of the war and the slaves’ freedom as its great moral accomplishment. The “reconciliationist” view emphasized the common hardships endured by soldiers and citizens who were after all countrymen. There was also a white supremacist version that marginalized the role of slavery as a cause of the conflict (sound familiar?), but the main interpretive battle was between the first two.

It’s a long a complex and quite revolting story about this country we love, and you should read the book. But the gist of it is that in the interest of national reconciliation, the North—where, let’s face it, there was also no shortage of racists in the late 1800s—capitulated to a view of the war with which the South could be comfortable, as a battle that fully and finally unified a country that never really had been.

Gettysburg became organized basically around Pickett’s Charge, the last thrust of the Lost Cause. By the time of Woodrow Wilson—the first Southern-born president since Andrew Johnson had taken over from the slain Lincoln, and a militant segregationist—there was a 50-year commemoration of that battle attended by 50,000 veterans, not one of them black.

Meanwhile, historical memory was morphing into political reality. In Congress, the United States entered the era of the Southern committee barons whose influence on the making of national policy was obscenely out of proportion to either their numbers or the extent to which their views, particularly on race, reflected broader American sentiment. Accruing seniority and working the rules, Southerners (and yes, conservatives, they were all Democrats then; so what?) gained power. By Franklin Roosevelt’s time, of the House’s 10 most important committees, Southerners chaired nine. As for the Senate, all you need to know is this sentence, penned by the journalist William S. White in 1957: “The Senate might be described without too much violence to fact as the South’s unending revenge upon the North for Gettysburg.”

The Southerners used that power to one end far above all others: keep black people down. But then, starting in 1958, the Senate began to elect some liberals; and outside the halls of power, which is where change actually happens, a certain young charismatic minister was changing white minds and opening white hearts across the country, even a few in the South.

Next came the only years, roughly 1964 to sometime in the mid-1970s, depending on how you measure it, that the North vanquished the South politically since the Civil War. Many chairmanships changed hands; the racists were defeated and changed political parties; accommodation of the South was no longer something most Northerners and Westerners were interested in.

So that was all good, but that of course doesn’t end our story. The South, through the person of Californian Ronald Reagan, who gave a high-profile speech invoking “states’ rights” in the very town where erstwhile states’ righters had murdered Goodman, Schwerner, and Chaney in 1964, came roaring back. The Christian Coalition became a force. From 1980 until 2008, the Democrats did manage to win two presidential elections, but only because they put forward an all-Southern ticket that talked more about “family values” than most Democrats would have really preferred, even if they did understand the political reality.

Just as Blight observed a post-Civil War era that saw two world views, one fundamentally progressive and the other fundamentally reactionary, competing to interpret the past and thereby define the future, I argue that we’ve been living through something very similar since 1980. And just like the emancipationists and reconciliationists, we’re stuck in the ’60s: They were quarreling about the 1860s, we about the 1960s. And in our political culture for most of the past 35 years, the modern-day version of the reconciliationists has won.

But now that’s changing. Fortunately, the emancipationists control the culture from New York and Hollywood, and they’ve pushed back on the Southerners hard—this too is a huge change from the old days, when for example television networks were extremely careful not to offend Southern tastes. And so even the Southern Baptist Convention has quieted down about same-sex marriage, even if the Republican candidates haven’t.

But this—this flag business is the first instance I can recall of conservative Republican Southern politicians defying their right-wing base on an issue of first-order emotional importance. It’s important that this isn’t some liberal federal judge ordering the flag removed. It’s Republican politicians doing it. I’m not saying that to pat them on the back—they’re at least a decade late to be getting anything resembling credit as far as I’m concerned. I’m just observing it as telling: When future David Blights write about how the South started losing its hold on America’s political culture in 2015, they’ll write about this moment, the first time their leaders said to them, “Your position is just too morally undignified for me to defend anymore.”

For his part, the actual living David Blight isn’t as hopeful about this as I am. In response to my question, he emailed me yesterday: “This may indeed be a rare moment. But if my work shows anything it might be simply to say beware when right-wing manipulators of historical memory offer reconciliation. They are looking for cover for other and perhaps larger matters.”

He’s correct, of course. This massacre is still about guns and terrorism, and it’s about South Carolina’s voter-ID laws too, on which Clementa Pinckney was one of just two favorable votes in the state Senate. All those fights will continue, with the usual achingly slow progress (if progress at all on guns).

But this is still a big deal. It could usher in a second era of conquest over Southern political hegemony. If that happens, those other fights will be easier to win, eventually, too.