( CNN) Anyone who wonders about the link between hateful menaces and actual violence was given something serious and grave to think about this week. Authorities received several pipe bombs delivered to people and organizations that for years have been on the receiving aim of a inundation of right-wing loathe speech.

We don't know who did this, though authorities suspect all the devices were made by the same person or group. It's a sad commentary on our times that the motivations could be multiple. Sowing or threatening violence in many places over a short space of time is a classic tactic of terrorists, and others who wish to destabilize society — for example, ahead of an important political event.

The midterm elections, coming up in less than two weeks, fit this bill. Republican Party efforts at voter suppression have constructed for a tense climate that President Donald Trump has worsened by insinuatingthat Democrat, whom he calls an “angry, leftist rabble, ” may commit voter fraud.

See photos of suspicious package sent to CNN

Hillary Clinton: It is a troubling time