My predictions:
1) They're not going to find this "bomber" before midterms
2) There will be a few more "suspicious packages" delivered. Wouldn't surprise me to see Jim Carrey, Behar, Alec Baldwin, one of the late night hosts, Rosie or the Amazon guy get something similar. Anybody who's been vocally opposed to Trump essentially
3) People like Mario Cuomo will claim that his regular issue of Maxim came in a "suspicious package" just so he can get some air time.
4) When midterms are over, the outrage will fade quickly. Nobody's talking about the packages sent to Trump's kids, the general, the brave Senator from Maine, etc.
5) The left will continue to blame Trump and that will become the drumbeat narrative of the mass media despite Mad Maxine calling for insurrection, Rosie demanding the army "take Trump out", Snoop portraying Trump's assassination, Eric Holder and Corey Booker ranting about physical altercations, despite Antifa, etc.
When this person is eventually caught (as he/she will probably be) you can look for one of these things:
1) The person will be a left-wing nut looking to damage Trump and mad about whatever. In this case the media will downplay it as the act of one crazed lunatic and not representative of the whole.
2) The person will be a right-wing nut, thinking he's defending the cause. In this case, the media will trumpet it from the top of the building claiming that he/she is representative of the entire base.
3) The person will be employed by the Clinton campaign. In this case the person will be killed in the street and evidence will vanish.