I generally always deny conspiracy theories, but I would actually give this about a 40% chance of being a liberal conspiracy. For there to be that many bombs and have all of them conveniently be faulty could cause suspicion. However, given that they all probably came from the same source, they could have just been made by a bad bomb-maker. The main thing is, even though this thought has crossed all of our minds, the conservative media and politicians need to resist the urge to share this theory. If they do, that would be exactly what the conspirators would want.
Even though I would not at all be shocked if this were a liberal conspiracy, I’m still saying 60% chance it was some Timothy McVae anarchist type. These things do happen, unfortunately.