The fake bomb gambit is totally a false flag operation. The objective is to take control of the media narrative, smear the Donald and negate his “jobs not mobs” slogan that was scoring direct hits.
I bet some left wing professor with connections to Antifa dreamed this up. A bonus would be if Bill Ayers is the culprit. He is a big fan of terrorist bombings.
From what I understand, all the fake bombs were not delivered by US Postal Service but by some mysterious courier or by personal delivery.
No cancelled stamps or post marks and no courier slips.
All of the places where bombs were delivered could have had willing accomplices to place the bombs for political purposes. So that is my guess: the bombs were allowed to be placed with cooperation or at least foreknowledge of the so-called victims.