The ignoramus wing of the Republican Party has for some time now been purveying a caricature of the intellectual as someone who is elitist, arrogant, smugly certain, impractical, and out of touch with the common man if not with reality itself.
In fact, anyone who actually has met (say) a college professor knows that most are earnest, deeply knowledgeable in their field while cautious about the inherent limits of human knowledge, open to differing opinions while instinctively skeptical toward crackpot ideas. Of course there are exceptions but as a rule true scholarship leads to humility, not arrogance, and the recognition that most problems we face as individuals and societies are complex, involve usually difficult and imperfect trade-offs between equally worthy but incompatible goals, and that having one's own ideas challenged is a necessary ordeal on the road to truth. Real intellectuals, as opposed to hucksters, do not sign "Ph.D." after their name.
I have been perplexed for some time why Newt Gingrich is routinely acknowledged even by his bitter enemies within the Republican Party as a "genius," but the answer turns out is simple: he acts exactly like one of those obnoxious elitist intellectual know-it-alls that the right-wing no-nothings think is the hallmark of an intellectual. He is constantly reminding us of his doctorate in history; he routinely claims he understands issues more deeply than anyone else; he has made a career of denouncing or (when he had the authority) eliminating professional expertise that might challenge his own certain pronouncements; and he is a veritable fount of crackpot "big" ideas (mining minerals on the moon, protecting the United States from sci-fi doomsday scenarios, and "fundamentally transforming" everything as a first step to doing anything.
Another useful rule of thumb: real geniuses, as opposed to simple egomaniacs, do not generally refer to themselves in the third person.