Let me offer another perspective. Radicals do serve a purpose.
Consider the PLO. Murderous thugs, in my book. Disgusting atrocities that should have resulted in the leaders and their troops hanging from a rope. But, it worked for them. Without the PLO, who would have cared one bit about the Palestinians? Would Israel ever have negotiated with them if the PLO had not taken up arms? Personally, I doubt it.
I think it is an unfortunate human quality that radicals perform this 'service'. In essence, they can move the pendulum, and make the previously 'radical' relatively more mainstream. With enough 'Shoemakers', the NRA, GOA and JPFO look positively tame.
So, was Shoemaker right? IMHO, he sounded as though neither 'oar' was in the water. OTOH, a few Shoemakers, a few 'Window War' skirmishes, Tyranny Response Team protests and other actions can put a finer point on this debate.
I do know this. The anti-self defense movement will be forced to realize that their brand of fascism will not be accepted without resistance. Each person on the side of the RKBA will need to decide whether they will simply stand quietly by, or whether they will take some action to prevent the continued destruction of the RKBA. And, by logical extension for many of us, further serious damage to the Bill of Rights.
Personally, I'll never use violence except to defend innocent life. But, I can believe that some of us, perhaps many of us, will be arrested in 'civil rights' protests over the next few years. With luck, perhaps a change in administration will help move the pendulum back, and all of this aggravation can be avoided.
Regards from AZ