PITY the poor word “elite,” which simply means “the best” as an adjective and “the best of a group” as a noun. What was once an accolade has turned poisonous in American public life over the past 40 years, as both the left and the right have twisted it into a code word meaning “not one of us.” But the newest and most ominous wrinkle in the denigration of all things elite is that the slur is being applied to knowledge itself.

Senator Hillary Clinton’s use of the phrase “elite opinion” to dismiss the near unanimous opposition of economists to her proposal for a gas tax holiday was a landmark in the use of elite to attack expertise supposedly beyond the comprehension of average Americans. One might as well say that there is no point in consulting musicians about music or ichthyologists about fish.

The assault on “elite” did not begin with politicians, although it does have political antecedents in sneers directed at “eggheads” during the anti-Communist crusades of the 1950s. The broader cultural perversion of its meaning dates from the late 1960s, when the academic left pinned the label on faculty members who resisted the establishment of separate departments for what were then called “minority studies.” In this case, two distinct faculty groups were tarred with elitism — those who wanted to incorporate black and women’s studies into the core curriculum, and those who thought that blacks and women had produced nothing worthy of study. Instead of elitist, the former group should have been described as “inclusionary” and the latter as “bigoted.”

The second stage of elite-bashing was conceived by the cultural and political right. Conservative intellectuals who rose to prominence during the Reagan administration managed the neat trick of reversing the ’60s usage of “elite” by applying it as a slur to the left alone. “Elite,” often rendered in the plural, became synonymous with “limousine liberals” who opposed supposedly normative American values. That the right-wing intellectual establishment also constituted a powerful elite was somehow obscured.

“Elite” and “elitist” do not, in a dictionary sense, mean the same thing. An elitist is someone who does believe in government by an elite few — an anti-democratic philosophy that has nothing to do with elite achievement. But the terms have become so conflated that Americans have come to consider both elite and elitist synonyms for snobbish.

All the older forms of elite-bashing have now devolved into a kind of aggressive denial of the threat to American democracy posed by public ignorance.

During the past few months, I have received hundreds of e-mail messages calling me an elitist for drawing attention to America’s knowledge deficit. One of the most memorable came from a man who objected to my citation of a statistic, from a 2006 National Geographic-Roper survey, indicating that nearly two-thirds of Americans age 18 to 24 cannot find Iraq on a map. “Why should I care whether my mechanic knows where Iraq is, as long as he knows how to fix my car?” the man asked.

But what could be more elitist than the idea that a mechanic cannot be expected to know the location of a country where thousands of Americans of his own generation are fighting and dying?

After listening to one of my lectures, a college student told me that it was elitist to express alarm that one in four Americans, according to the National Constitution Center, cannot name any First Amendment rights or that 62 percent cannot name the three branches of government. “You don’t need to have that in your head,” the student said, “because you can just look it up on the Web.”

True, but how can an information-seeker know what to look for if he or she does not know that the Bill of Rights exists? There is no point-and-click formula for accumulating a body of knowledge needed to make sense of isolated facts.

It is past time to retire the sliming of elite knowledge and education from public discourse. Do we want mediocre schools or the best education for our children? If we need an operation, do we want an ordinary surgeon or the best, most elite surgeon available?

America was never imagined as a democracy of dumbness. The Declaration of Independence and the Constitution were written by an elite group of leaders, and although their dream was limited to white men, it held the seeds of a future in which anyone might aspire to the highest — let us say it out loud, elite — level of achievement.