There is a line in one of the Harry Potter books where Professor McGonagall tells Harry to, “Do use your common sense!” Little did J. K. Rowling know when she wrote that line she would be inspiring advice to conservatives on how to defeat liberalism.
The term, “common sense,” as defined by Merriam-Webster’s online dictionary is, “sound and prudent judgment based on a simple perception of the situation or facts.” [Emphasis mine] This is an immediate and direct observation of something, rather than a transfer of perception to you from some other indirect authority. The word, “common,” in this phrase implies that it uses the senses that most everybody has; smell, touch, sight, sound, etc. If, for example, I tell you I want you to tell me what the sky looks like you have two options. You can go out and look at the sky for yourself and develop your own opinion on what the sky actually looks like to you or you could go to the Weather Channel and get someone else’s opinion, having never seen the sky for yourself. I cannot emphasize enough that the latter of these two options is not common sense! This is because the senses commonly available to most human beings were not directly used to perceive what the sky looks like. It is the simple difference between an opinion and a fact.
Continuing on this line of logic let us suppose that you return from your adventurous expedition to the wonderful world of the outside and report to me the simple and direct observation that the sky is blue. Let us also suppose that I choose to disbelieve your report based on the fact that I went to the Weather Channel which claimed that there would be nothing but solid and constant rain today. Thus we have a difference of opinion. One is based on the senses most common to almost all of us. The other is based purely on an opinion derived from a disreputable authority. And have no doubt ever that this is how a weatherman’s reputation is earned.