Discrimination by sex and by race are ancient innate pathologies and transcend particular cultures. But the American idea of sexismand racism in the 21st century — unfailing, endemic, and institutional discrimination by a majority-white-male-privileged culture against both women and so-called non-white minorities — has largely become a leftist construct.

We can see how these two relativist -isms work in a variety of ways.

One, the frequent charge of racism and sexism is predicated not so much on one’s gender and race as on one’s gender, race, and politics. Certainly, few on the left worried much about the slurs against Sarah Palin during and after her vice-presidential run. America’s overclass in the media and leftist politics constructed a sexist portrait of a clueless white-trash mom in Wasilla, Alaska, mindlessly having lots of kids after barely graduating from the University of Idaho. Even Bill Maher’s and David Letterman’s liberal armor would not have withstood leftist thrusts had, mutatis mutandis, the former called Hillary Clinton a c–t or the latter disparaged Ms. Clinton as “slutty flight attendant” and joked that, when a teen, Chelsea Clinton had had sexual relations with a Yankee baseball player in the dugout. Ironically it was the by-her-own-bootstraps lower-middle-class Palin who braved the frontier, no-prisoners, male world to become governor of Alaska; in real terms, she is the true feminist. In contrast, according to doctrinaire feminism, Hillary Clinton does not measure up. She has largely clung, in mousy fashion, to her two-timing husband, excused his serial and manipulative philandering with young women of less clout and power, traded on his political nomenclature, and piggy-backed on his career.

Leftism assumes that racist and sexist speech by liberals constitutes good people’s lapses of judgment and tact.

The Black Caucus rarely if ever comes to the defense of Justice Clarence Thomas when, periodically, liberal commentators suggest that he was and is unqualified, and is largely a token black conservative. No one suggests that the New York Times is on an anti-Latino crusade against Marco Rubio in trying to fashion a story of recklessness from the paltry evidence of his receiving one traffic ticket every four years. Had candidate Mitt Romney suggested, as did Senators Joe Biden and Harry Reid, that Senator Barack Obama was a “clean” and “light-skinned” black man without “a Negro dialect,” he would have been considered little more than a Clive Bundy buffoon and would have had to drop out of the Republican primary.

It appears that leftism assumes that racist and sexist speech by liberals constitutes good people’s lapses of judgment and tact — not, as in the case of conservatives, valuable windows into the dark hearts of bigots. In other words, the idea of sexism and racism is not absolute, but relative and mostly socially massaged and constructed by politics. Had President Bill Clinton declared during the O. J. trial that if he had had a second daughter she would have resembled Nicole Simpson, the media and popular culture would have excused such a sick Obamism as a quirky slip — in a way that it would not have if a Bob Dole had uttered the same banality and thereby supposedly revealed his poorly suppressed racist proclivities.

A second tenet of socially constructed racism and sexism is “white privilege,” which usually translates into “white male privilege,” given that women such as Hillary Clinton and Elizabeth Warren are rarely accused of being multimillionaire white elite females who won a leg up by virtue of their skin color. But if whiteness ipso facto earns one advantages over the non-white, why in the world do some elite whites choose to reconstruct their identities as non-white? Would Elizabeth Warren really have become a Harvard law professor had she not, during her long years of academic ascent, identified herself (at least privately, on universities’ pedigree forms) as a Native American? Ward Churchill, with his beads and Indian get-up, won a university career that otherwise might have been scuttled by his mediocrity, his pathological untruths, and his aberrant behavior. Why would the current head of the NAACP in Spokane, Wash., a white middle-class woman named Rachel Dolezal, go to the trouble of faking a genealogy, using skin cosmetics and hair styling, and constructing false racist enemies to ensure that she was accepted as a victimized black woman?

Ms. Dolezal assumed that being a liberal black woman brought with it career opportunities in activist groups and academia otherwise beyond her reach.

The obvious inference is that Ms. Dolezal assumed that being a liberal black woman brought with it career opportunities in activist groups and academia otherwise beyond her reach as a middle-class white female of so-so talent. Critics will object that we are really arguing in class terms as well as racial terms: Privileged whites play on society’s innate prejudices against darker-skinned minorities by positioning themselves as light-skinned, elite people of color. That is a Pandora’s box that is better left unopened — given that Harry Reid and Joe Biden have already unknowingly pried open the lid on these matters in ways that would transcend Barack Obama and equally apply, for example, to Eric Holder or Valerie Jarrett.

Suffice it to say that in our increasingly intermarried, assimilated, and integrated culture, it is often hard to ascertain someone’s exact race or ethnicity. That confusion allows identity to be massaged and reinvented. That said, it is also generally felt among elites that feigning minority status earns career advantages that outweigh the downside of being identified as non-white in the popular culture. That was certainly my impression as a professor for over 20 years in the California State University system watching dozens of upper-class Latin Americans — largely white male Argentinians, Chileans, and Brazilians — and Spaniards flock to American academia, add accents to their names, trill their R’s, and feign ethnic solidarity with their students who were of Oaxacan and Native American backgrounds.

Poor George Zimmerman. His last name stereotyped him as some sort of Germanic gun nut. But had he just ethnicized his maternal half-Afro Peruvian identity and reemerged as Jorgé Mesa, Zimmerman would have largely escaped charges of racism. He should have taken a cue from Barack Obama, who sometime in his late teens at Occidental College discovered that the exotic nomenclature of Barack Obama radiated a minority edge, in a way that the name of his alter ego, Barry Soetoro, apparently never quite had. If, in America’s racist past, majority culture once jealously protected its white privilege by one-drop-of-blood racial distinctions, postmodern America has now come full circle and done the same in reverse — because the construction of minority identity, in all its varying degrees, is easily possible and, in ironic fashion, now brings with it particular elite career advantages.

Third, when we look at questions of class, we see again that racism and sexism are largely leftist constructs and not empirical terms describing millions of Americans who are supposedly denied opportunity by the white establishment because of their gender or race. The CEOs in the industries of sexism and classism are for the most part wealthy and privileged — and their targets are usually of the middle class. When Michelle Obama labors to remind her young African-American audiences of all the stares and second looks she imagines she still receives as First Lady, she is reconstructing a racial identity to balance the enormous privilege she enjoys as a jumbo-jet-setting grandee who junkets to the world’s toniest resorts with regularity. The 2016 version of Hillary Clinton is, at least for a few months, a feminist populist, and has become so merely by mouthing a few banal talking points. Apparently the downside for Hillary of being a woman is not trumped by the facts of being a multimillionaire insider and former secretary of state, wife to a multimillionaire ex-president, mother of a multimillionaire, and mother-in-law to a multimillionaire hedge-fund director. Hillary can become a perpetual constructed victim, denied the good life that is enjoyed by a white male bus driver in Bakersfield making $40,000 a year.

Given the construction of race and gender, the children of Eric Holder and Barack Obama will be eligible for affirmative-action consideration out of reach for an 18-year-old white male in Provo, Utah. As a general rule, when advising classics majors who wished to apply to Ph.D. programs, I assumed that a white male needed a near-perfect GRE score and GPAs, to avoid being rejected out of hand as a middle-class so-so white man from Fresno State. (I reminded them that the “system” assumed their white privilege had given them advantages from preschool onward that the Ivy League and the University of California system now had to adjust for.) For my minority classics students, on the other hand, admission was rarely a problem, despite the fact that many were of a higher social class than their mostly rejected white counterparts.

Fourth, sexism and racism are abstractions of the liberal elite that rarely translate into praxis. Barack Obama could have done symbolic wonders for the public schools by taking his kids out of Sidwell Friends and putting them into the D.C. school system. Elizabeth Warren could have cemented her feminist populist fides by vowing to stop flipping houses. Feminist Bill Clinton could have renounced all affairs with female subordinates. Eric Holder could have vowed never to use government jets to take his kids to horse races. In solidarity with co-eds struggling with student loans, Hillary Clinton could have promised to limit her university speaking fees to a thousand dollars per minute rather than the ten thousand dollars for each 60 seconds of chatting that she actually gets, and she might have prefaced her public attacks on hedge funds by dressing down her son-in-law. Surely the lords of Silicon Valley might have promised to keep their kids in the public schools, and funded scholarships to allow minorities to flood Sacred Heart and the Menlo School.

Charges of racism and sexism have little to do with demonstrable racial and sexual prejudice on the part of a white-male establishment. They are relative, not absolute, phenomena, and more often constructed by political beliefs and careerist concerns than observed independently. Such concepts are often entirely divorced from class reality, and often have more to do with illiberal privilege than with actual exclusion.