Not that they don't have the capacity to engage in sporadic violence, but the far right militias preparing for civil war aren't going anywhere. The people inclined to participate in those long ago realized they can make a greater impact by joining security forces - police, military, border patrol - and have been doing so.
There just aren't the conditions needed for civil war, so talking about it as a counterfactual becomes very difficult. The most plausible scenario for these guys to live out their dreams is in siding with a right-wing President against lawful removal from office. But they'll have the military at that point, so there's no actual war to speak of. There's no one to fight.