How to define common sense can be somewhat of a mystery. It varies with the individual attempting the definition and that leads to as many disparate opinions as there are people 'inclined to define.'
Common sense is defined by Merriam-Webster as, "sound and prudent judgment based on a simple perception of the situation or facts."Thus, "common sense" (in this view) equates to the knowledge and experience which most people already have, or which the person using the term believes that they do or should have. The Cambridge Dictionary defines it as, "the basic level of practical knowledge and judgment that we all need to help us live in a reasonable and safe way."
"Living in a reasonable and safe way" is good for starters. Being safe could mean that we don't fall prey to those who would do us harm, those who would take from us what little we have-physically, mentally and even spiritually, and that we don't become what we intrinsically have a revulsion to.
Common sense depends a lot on trust. Trust in ourselves, trust in others and the ability to see through deceptions. It's not an easy task.
To see Clinton on a podium marked 'the value of common sense' is an affront to our sensibilities. To hear most politicians or those in the controlled media speak their brand of common sense reveals an agenda that only money can buy. To feel the effects of the so called elite's so called common sense is to feel pain.
Maintaining the pain for many for the profit of a few is but one example...
As individuals we can have all the common sense in the world but without action it is of little use. The elite see their version of common sense as a tool for control and as long as we remain paralyzed our lack of action seems to prove to them that they deserve to dictate our destiny.
Collectively we do have the common sense to overcome the mass manipulations that ail us. Perhaps the first step is to reject the divide and conquer techniques that envelop us? After that it's just one small common sense step at a time.