In what way, in fact, is that the logic of the "pro-gun party?" I myself have not heard the NRA or others ever say that non-gun owners deserve to die. Please elaborate.

They say that "guns protect us". How do they protect us? Is a bystander supposed to lift up their shirt, revealing a gun tucked into their waist, forcing the bank robbers to run away? I think the NRA and Republican party have already assumed that they're instructing the general public to kill, or at least wound, on behalf of public safety.

Having the ability and/or willingness to protect others is entirely different from mandating it. The NRA is asking for the ability to exercise the right to defend oneself (and others) if needed, without censure. You would require that civilians purposefully put themselves in that situation - to go looking for trouble - in order to have that right of defense.