First I must add that I remember when guns even surplus WWII weapons were sold in magazine ads and IIRC comic book ads. I remember when DoD virtually gave away surplus ammo -- there's something else going on today.
I agree with the writer.. but I must add that there is at least one other factor today that just was not there back then.. widespread use of mind-altering pharmaceuticals
Was this and other massacres "arranged" in order to advance an agenda.
Maybe yes in the context that certain pharmaceuticals have effects on the mind that, there is strong evidence, cause these horrors.
Yet, and here's the "arranged" aspect, there appears to be a disregard and even a coverup of the connection -- it could be argued that some in the ruling class New Normal want the shootings to happen
and among them there was talk that it may be necessary to kill as many as 60 million Americans to get their desired transformation of America. They need to disarm those 60 million Americans.
(There's one more thing that we have today that we did not have back then when these aged Marxist-Alinsky campus radical, spoiled brats were children -- a couple of whom produced Barack Obama. That other thing is these pukes are now in the ruling class.)