As I ponder the "common thread" you mention, those folks who holler at 2A enthusiasts to justify why America has to be different from other "safer" countries like England, Australia, France etc come to mind. Those opposed to the rights mentioned in the Second Amendment always bring this "difference" up as if the reason for our oneness is a malady crying for a cure, or that our uniqueness itself is the disease. And as such, they make the appearance that "we" share no common thread with "them".
It is true that no other nation allows it's citizens to so freely possess firearms. Very well, then, we're different - but just look at us. Look at what we are: the greatest, most powerful and technologically advanced nation in the world, built and populated by people of inter-bred nationalities, a "nation of immigrants". A country comprised of human beings who either came here from another country or are descendants of those who did. In that regard, America does indeed stand unique in the world, because all the world's offspring congregated on these shores to build something magnificent.
Therein lies the difference between the citizens residing in Germany, and the Germans who came here; the French still in France, and those who ventured to America; the English in London compared to the Brits who crossed the ocean to these shores - they, and we their descendants, were never Germans, never French, never English to begin with.
Our immediate ancestors were born Seekers. Those who were destined to leave their motherlands were born with an innate yearning for freedom more intense than that of their own countrymen.
They were, from birth, Americans.
We're not "different" because we're Americans. We're Americans because we're different.
America needs to stop seeking forgiveness from the rest of the world or apologizing to the United Nations for the very trait that embodies why we are so different: individual freedom, individual possessions as the fruit of individual labor, and having the will and the means to defend them solely define liberty, define America and make vivid our proud and magnificent singularity among all other nations.
This isn't Piers Morgan's England. It's not Australia or France.
From its birth, America was always intended to be different, built and populated by seekers from all lands, to stand deliberately alone, immovably proud in our oneness.
I guess my point is, this "common thread" that binds us all here ought be the thread that binds ALL Americans. I pray someday it will be.