Let us imagine for a moment that a woman came forth claiming that Barack Obama had sexually harassed her fifteen years ago. What would the reaction be from liberal partisans, and assorted other supporters? We can easily imagine that there would be urgent questions about the motivations of the woman who came forward, and the media outlets that broke the news. There would likely be a furious attendance to the possibly “racist” aspects of the coverage. There would be an almost cavalier neglect of the gravity of the charge itself, as if it were somehow utterly beyond consideration that Obama had actually done it. And if the accuser were white, well, that would only further fuel liberal suspicions.

In short, the response to such allegations against Obama would involve playing the race card—and it would bear a strong resemblance to the way Herman Cain has responded to his own sexual harassment scandal. The left has been outraged at the Cain campaign’s response, but it also ought to feel a pang of recognition. If the race card is still a viable part of our national discourse in the Obama era, it is so at the behest of liberals—and it’s no less odious or callow when it is played by the left as when it is by the right.

Yes, such claims are generally more cynical, and less coherent, when they are deployed by conservatives. It borders on absurdity that the very conservatives who have harped on the importance of “moving past” racism are defending Cain as a victim of discrimination. In any case, the charges against Cain have become so concrete that it is cartoonish to pretend that racism is truly what is at stake.

But most of the left’s invocations of racism have also, in any objective sense, lost credibility—not because they follow Cain in trying to contradict specific facts, but because they have become so omnipresent and vague as to lose all meaning. Liberals imagine they are fighting the good fight, that they are uncovering truths about the hidden role of racism in the world. But what they have really been doing is making a dogma of racial grievance, one that has been exploited repeatedly by public figures on the left—and was bound to inevitably be deployed by politicians on the right.

This has become especially egregious in the last several years, as liberals have serially suggested that Obama’s political detractors are all insidiously motivated by bigotry. This is an agenda that goes beyond pointing out the occasional mean T-shirt or sign, or scattered tacky eruptions like Rep. Joe Wilson’s “You lie!” eruption during a State of the Union address two years ago. That would be too anodyne: We all already presume that there are backwards individuals in our society, flies in the ointment.

What liberals prefer to suggest is that there would be no vehement opposition to the White House, no Tea Party—or at least a kinder, gentler Tea Party—if Hillary Clinton were President and following the same line as Obama. Or that liberals would have all fallen into line if Obama’s current agenda were being peddled by a President John Edwards. This is not an empirical inquiry into specific instances of racism; it is a theory about the nature of country’s current agitation—namely, that it is informed by a general racial malice.

It is a seductive theory, but a dubious one. One need only look to the recent past to confirm that conservatives have harbored dogmatic suspicions of Democratic presidents long before one of them was black. Bill Clinton was pointedly despised by a great many, long before he was caught up in Monicagate. Who can forget the right-wing columnists and operators (mostly white then, as they are today), salivating to out him and his wife as malevolent moral monsters on the basis of Whitewater, Travelgate and such? As early as 1994, the satirical prime-time animated sitcom The Critic had a gag where a newspaper described the 1992 presidential election with the headline “Lecherous Hillbilly Elected”. (One need only imagine the outcry if anything as pitiless would be indicated about Obama on, say, Family Guy.) Or, remember the weird emails that circulated attempting to link the Clintons to assorted deaths and murders, with Vince Foster just the tip of the iceberg?

There wasn’t an internet back then to make all of this vitriol as omnipresent then as it is now (or as easily recoverable). But the difference in tone was minor. One suspects that racial suspicions of some younger writers, so deeply appalled at how Obama is discussed now, is the product of naïveté, the fact that they happened to miss the way conservatives and liberals alike seemed to almost recreationally revel in the sour resonance that the Clintons evoked in the 1990s.

Liberals have also been implicitly playing a race card by imagining and demanding a tribal allegiance among African-Americans that conservative blacks are said to somehow be betraying. To insist that the reason Republicans like Cain is because he is a “minstrel” dancing to their tune is playing the race card. If Republicans like a white person for sharing their opinions, is the white person “dancing to their tune”? How about Thomas Sowell? Do his decades of densely reasoned conservatism qualify as a mere dance? Should one even be expected to substantially engage with his work before making such allegations?

Okay: Cain’s views are hardly as well reasoned as Sowell’s. But then neither are those of most of the people currently elevated by Republicans as serious figures. We ought to be assessing people by the content of their character—and that means allowing that Herman Cain has as much right to be a dumb Republican as any white person.

Liberals have not only failed to acquit themselves well with their self-righteous deployments of race allegations—they have encouraged conservatives to follow their lead. Conservatives, unsurprisingly, have acquitted themselves equally poorly. The clip of Clarence Thomas making his “high-tech lynching” claim looks worse by the year. The one from last week of Cain on Fox News—when asked whether racism is behind the charges, all he came up with was “I believe the answer is yes, but we do not have any evidence to support it”—now joins it as a quintessential demonstration of flabby reasoning and sociopolitical cynicism.

But liberals should keep in mind that they’re the ones who have enabled this kind of thing. They may have cloaked their conspiracy theories with scientific terms like “institutional racism” and “legacy”, but the hollowness of their logic and the density of their paranoia is the same.

John McWhorter is a contributing editor for The New Republic.