LAST week’s Republican primary in Tennessee resulted in a comfortable win for Senator Lamar Alexander over his Tea Party-backed challenger, State Assembly Representative Joe Carr. But make no mistake: The Tea Party is on a roll across the South, having mounted major primary challenges in Texas, Mississippi and South Carolina, and knocked out Representative Eric Cantor of Virginia.

The movement’s success, with its dangerous froth of anti-Washington posturing and barely concealed racial animus, raises an important question for Southern voters: Will they remember their history well enough to reject the siren song of nativism and populism that has won over the region so often before?

We often think of the typical segregationist politician of yore as a genteel member of the white upper crust. But the more common mode was the fiery populist. Names like Thomas E. Watson of Georgia, “Pitchfork” Ben Tillman of South Carolina and James K. Vardaman and Theodore G. Bilbo of Mississippi may be obscure outside the South, but for most anyone brought up here, they loom large.

In the early 20th century, these men rose on an agrarian revolt against Big Business and government corruption. They used that energy, in turn, to disenfranchise and segregate blacks, whose loyalty to the pro-business Republican Party made them targets of these racist reformers.

Their activities spawned a second wave of Southern Democratic populists, who defied federal court orders and civil rights legislation during the 1960s, even as more moderate politicians were moving on. Gov. George C. Wallace of Alabama, among others, portrayed himself as a tribune of the working class while championing segregation.

It’s hard not to hear echoes of those eras today. Tea Party candidates have targeted federal taxes and spending, while attacking Chamber of Commerce interests and the leadership of the Republican Party. Racism has been replaced with nativism in their demands for immigration restrictions, but the animosity toward the “other” is the same. And there remains a whiff of the ancient fumes of bitter-end resistance: Chris McDaniel, a state senator who took Senator Thad Cochran into a runoff in Mississippi, still refuses to accept the validity of the election.

Mr. McDaniel had all the bona fides of an old-time demagogue. He was once a conservative radio talk show host who dabbled in ethnic innuendo. He made appearances before neo-Confederate organizations. When Mr. Cochran solicited votes in the runoff from black Mississippians, Mr. McDaniel’s supporters vowed to monitor polling places in black-majority precincts, a move reminiscent of old-fashioned Election Day intimidation.

Tea Party spokesmen, as well as the Republican establishment, complain that the movement was unfairly trumped by a race card. Whit Ayres, a Republican pollster working for Mr. Alexander, says the movement isn’t racist, but rather it represents people “who are economically pressed, who feel betrayed, who feel leaders in Washington caused their housing values to decline, for their retirement accounts to plummet.”
But that’s precisely the point, and the hope, for those worried about the Tea Party insurgency. What looks like a mounting wave may have reached its crest this year, running up against the many Southerners — white and black, liberal and conservative — who know well how such passions were once perverted by demagogues.
It’s trite to recall William Faulkner’s line about the past not being the past, but Southerners do remember their history: A considerable body of literature about the populist rebellion was once required reading in college for a generation of Mississippians old enough to remember the second reactionary period 50 years ago.

In “The Mind of the South,” still in print seven decades after it was published, W. J. Cash wrote that populist forces in the region were driven by “the rage and frustration of men intolerably oppressed by conditions which they did not understand and which they could not control.” And A. D. Kirwan’s 1951 history, “Revolt of the Rednecks,” traced the political rise of the Mississippi racists Vardaman and Bilbo to the disillusionment of white farmers who felt “forgotten” and singled out by “an enemy class” of Wall Street speculators and railroad owners backed by big government. The economic struggle, Kirwan wrote, was “complicated by the Negro,” who became a victim of the politicians’ zeal to prevent blacks from holding any power.

Education became their whipping boy. A century ago, the first wave of populist demagogues withheld funds for poor, segregated schools and tried to purge college faculties of nonbelievers. The second wave, citing “states’ rights,” threatened to shut schools rather than integrate and denounced federal aid to education as a sinister investment. In the Cochran-McDaniel race, you could hear that same strain in Tea Party criticisms of the federal government, of federal aid to education and of the “establishment.”

Over a century ago, demagogues did more than anyone to impose the system of strict segregation that lasted until the 1960s. The second wave, though successful in some places, was turned back in others, by moderate, middle-class Southern whites who were tired of seeing their region isolated and stigmatized. With Mr. Cantor’s loss, Mr. Cochran’s narrow survival and Mr. Alexander’s clear victory, we are faced with an open, and very unsettling question: Which way will the South go this time?