Herman Cain’s presidential campaign has been cruising along without being derailed by either the candidate’s gaffes on foreign policy or abortion, but a bombshell story released by Politico on Sunday may profoundly impact the course of the Republican race. According to the website, Cain was accused by two separate women of inappropriate behavior during his time as CEO of the National Restaurant Association in the 1990s. According to sources cited in the article, the accusations amounted to sexual harassment. The story leads readers to believe the cases were dealt with by the organization, and both women received settlements in exchange for their silence. If true, this is nothing less than political dynamite that could blow up Cain’s presidential hopes at a time when he continues to compete with Mitt Romney for the GOP lead in national polls.

For many observers, this will seem vaguely similar to the incendiary charges leveled by Anita Hill at Supreme Court Justice Clarence Thomas during his confirmation hearings. The question now is not just whether the story is true but if Republican voters think Cain is being given a “high-tech lynching” (to repeat the words Thomas used to describe what happened to him).

The accusations against Thomas remain a source of controversy. The public is still divided as to the truth about the affair. During the years a liberal popular culture has treated Hill’s story as gospel, and more of the general public have come to see him as a sexual harasser than did at the time. But among conservatives, Thomas remains a hero not just because of his jurisprudence but because they seem him as an innocent victim of a media establishment out to humiliate and punish any African-American who stepped outside of the liberal consensus. There have already been clear signs that the left-wing leadership of American blacks has sought to brand Cain as an “Uncle Tom” in the same way they tried to tarnish Thomas.

There is, of course, plenty of hypocrisy to be found in cases where politics and sexual harassment intersect. Liberals were ready to burn Thomas at the stake based on the say so of one woman in 1991. Seven years later, they told the country to “move on” when Bill Clinton was accused of harassing Paula Jones and other women. Conservatives who voted to impeach Clinton may have claimed it was about the lying and not the sex, but they cannot afford to give a pass to anyone — even a popular presidential candidate — who is now accused of the same serious crime.

The initial reaction from most Republicans will be to doubt Cain’s accusers for this reason. The idea of a libidinous black man posing a threat to women is a racist notion deeply imbedded in American popular culture. This is the sort of thing the mainstream media would think twice about discussing were a liberal black being accused, but many conservatives will assume Cain is being singled out because of his politics. That could cause a GOP backlash that helps rather than hurts Cain’s candidacy.

That said, Cain needed to do better than the stonewall response he put forward when asked directly about the accusations on Sunday. Though he subsequently claimed on Monday in an interview on Fox News that he was falsely accused of sexual harassment and denied any wrongdoing, if those involved come forward with accusations, it will be a problem for him. If he is guilty or, as is also possible, if this is a murky controversy in which both sides have a case to make then there is no disguising the fact that the charge could prove fatal to his candidacy. The Clarence Thomas precedent notwithstanding, sexual harassment is not a trivial business. A credible accusation of this sort is a disqualifying flaw in a candidate. Those who believe the GOP can nominate a person with this sort of charge hanging over them and still win next November are kidding themselves.