Everyone knows that race has long played a decisive role in Southern electoral politics. From the end of Reconstruction until the beginning of the civil rights era, the story goes, the national Democratic Party made room for segregationist members — and as a result dominated the South. But in the 50s and 60s, Democrats embraced the civil rights movement, costing them the white Southern vote. Meanwhile, the Republican Party successfully wooed disaffected white racists with a “Southern strategy” that championed “states’ rights.”

It’s an easy story to believe, but this year two political scientists called it into question. In their book “The End of Southern Exceptionalism,” Richard Johnston of the University of Pennsylvania and Byron Shafer of the University of Wisconsin argue that the shift in the South from Democratic to Republican was overwhelmingly a question not of race but of economic growth. In the postwar era, they note, the South transformed itself from a backward region to an engine of the national economy, giving rise to a sizable new wealthy suburban class. This class, not surprisingly, began to vote for the party that best represented its economic interests: the G.O.P. Working-class whites, however — and here’s the surprise — even those in areas with large black populations, stayed loyal to the Democrats. (This was true until the 90s, when the nation as a whole turned rightward in Congressional voting.)

The two scholars support their claim with an extensive survey of election returns and voter surveys. To give just one example: in the 50s, among Southerners in the low-income tercile, 43 percent voted for Republican Presidential candidates, while in the high-income tercile, 53 percent voted Republican; by the 80s, those figures were 51 percent and 77 percent, respectively. Wealthy Southerners shifted rightward in droves but poorer ones didn’t.

To be sure, Shafer says, many whites in the South aggressively opposed liberal Democrats on race issues. “But when folks went to the polling booths,” he says, “they didn’t shoot off their own toes. They voted by their economic preferences, not racial preferences.” Shafer says these results should give liberals hope. “If Southern politics is about class and not race,” he says, “then they can get it back.”