Commentary by Gregory Rodriguez: Today, to declare yourself a redneck is to insist that you don't take your cues from New York, Washington or Los Angeles.

Irascible rednecks are nothing new in politics. Once upon a time, they tended to be either marginal firebrands like George Wallace or, more recently, the ne'er-do-well, embarrassing siblings of well-educated Southern pols — think Billy Carter or even Roger Clinton. But nowadays they seem to be the mainstream politicians themselves.

In April, Haley Barbour, governor of Mississippi, former national GOP chairman and potential 2012 presidential candidate, referred to himself as "a fat redneck" on CNN's "John King USA." In May, Sarah Palin embraced the redneck label during her speech at the National Rifle Association's annual convention in Charlotte, N.C. She then rifled off a list of "you know you're a redneck when" jokes. (The funniest, I thought, was "you know you're a redneck if you yell at your husband to move the transmission so you can take a bath.")

Then, two weeks ago, after local Republican Party officials censured him for using an ethnic slur to describe President Obama and South Carolina gubernatorial hopeful Nikki Haley, South Carolina state Sen. Jake Knotts took to the Senate floor in Columbia. He started by complaining that no one came to his defense when he was called a redneck and ended by proudly claiming the title, saying that the true meaning is a farmer who works in the sun from dawn to dusk.

To many Northerners, "redneck" is just code for uncouth Southern racist, and Knotts' slurs don't do much to counter that impression. But as his contorted self-defense suggests, redneck is a complex, marginal and oppositional identity.

Terms like "redneck" and "white trash" were first used in the 19th century by upper-class whites to classify their poorer cousins. They are essentially the product of the ideology of white supremacy. If, as Southern slave owners argued to justify the enslavement of Africans, whites were a superior race, then those whites who did not exhibit "superior" qualities had to be identified and taken down a notch. In other words, poor, rural, uneducated whites were deemed something less than fully white. Northern abolitionists also used poor Southern whites to further their agenda. They considered rednecks uniquely depraved and living proof that the evils of slavery undermined social morality.

More than a century later, during the civil rights era, rednecks became an easy scapegoat for guilty, middle-class Northerners and Southerners — as if poor whites were somehow more responsible than everyone else for the country's racial sins.

But poor whites gradually redefined the meaning of the terms. If to elites "redneck" or "white trash" meant deserved poverty and menial labor, to many poor whites it came to mean suffering unfairly and hard work. While the Southern gentry may have found rednecks' lack of education vulgar and coarse, rednecks came to see themselves as frank, commonsensical and having no airs. By the 1970s, redneck also implied a form of authenticity even as the identity jumped far beyond its Southern origins.

Today, to declare yourself a redneck is to insist that you don't take your cues from New York, Washington or Los Angeles. To call yourself a redneck is to thumb your nose at highfalutin propriety and to revel in a lack of sophistication. Redneck is an identity based on having a chip on your shoulder but not simply — as some insist — because of the gains made by blacks. Redneck resentment doesn't so much stem from losing "white privilege," it stems from never having had a crack at that privilege in the first place.

Knotts threw that resentment back at his fellow Republicans in his speech in South Carolina, and he uttered a political threat that sounded a lot like any minority activist flexing his political muscle. "If all of us rednecks leave the Republican Party, the party is going to have one hell of a void," he said. But unlike most nonwhite activists, Knotts and other redneck pols don't sound aspirational. Their rhetoric is less about demanding change and help so they can advance than it is about hunkering down in their historical beleaguerment.

So here's the real redneck joke: You know you're a redneck when you're mad as hell and you just want to spread it around. Especially in the midterm elections of 2010.

Gregory Rodriguez is a columnist for the Los Angeles Times. Readers may send him e-mail at grodriguez@latimescolumnists.com.