This morning, after a few minutes of online browsing, my girlfriend said to me – matter-of-factly over her cup of steaming coffee – that, "They say that Clinton won the debate last night."

I know why she said that, because I know that her go-to news source is Newser, which aggregates and summarizes stories and analyses from around the web. She had just read the aptly titled, "Debate Seen as Massive Win for Clinton" – a round-up of the conventional wisdom as offered by outlets like the Washington Post, the New York Times, and Politico.

Michael Barbaro and Amy Chozick of the New York Times, for instance, noted that Clinton, who had a "dominant performance," had "smiled and laughed regularly." Chris Cillizza of the Washington Post observed that, "Clinton was confident, relaxed and good-natured" and "was head and shoulders above everyone else on the stage as a debater." Niall Stanage and Amie Parnes of The Hill remarked that Clinton was "polished and poised."

If you're looking for evidence that she won on the merit of her ideas, you won't find it in these mainstream publications. Incidentally, these are the criteria that they must use in their assessments: adjudicating who gave the best answers would be to risk appearing "biased," which could damage their credibility with their large and diverse readerships.

It is the superficiality of the conventional wisdom – what Christopher Hitchens once described as often being "a hundred miles wide and a millimeter deep" – that ought to leave readers wondering on what basis the public should believe that Clinton truly won the debate.

Indeed, what sustains the conventional wisdom is not any kind of wisdom per se, but rather mere convention: Clinton is roundly declared to have won because others have said she won. It is similar to the logic that drives celebrity culture, in which people are well known for being well known.

This is precisely why the Newser article title,"Debate Seen as Massive Win for Clinton," is so fitting, if not revealing. This is writing – and thinking – in the passive voice.

Perhaps the best encapsulation of how consensus opinion is generated and replicated comes from James Fenimore Cooper, who wrote in 1835:

"They say," is the monarch of this country, in a social sense. No one asks "who says it," so long as it is believed that "they say it." Designing men endeavor to persuade the public, that already "they say," what these designing men wish to be said, and the public is only too much disposed blindly to join in the cry of "they say."

It is this insight that voters should keep in mind when they are bombarded by opinion polls that tell them which candidates or ideas are popular and are thus considered politically viable, as well as when they read mainstream publications that, however subliminally, attempt to steer public opinion to support a particular candidate, issue, or mindset.

In order to inoculate one's self against this kind of groupthink, Cooper recommended that, "Every well meaning man, before he yields his faculties and intelligence to this sort of dictation, should first ask himself 'who' is 'they,' and on what authority 'they say' utters its mandates."

Most importantly, in addition to being skeptical of the flimsy basis of the conventional wisdom, voters should have confidence in their own ability to watch, listen, and read for themselves, to do their own research, and to form their own opinions – regardless of whether they align with the general consensus.