There is a crucial difference between most of the FRC’s critics and the wingnuts whose claims are accepted by right-wing shooters. SPLC declared FRC a hate group, but they did not accuse them of breaking the law or plotting violence.
In contrast, Alex Jones, Glenn Beck, et al, routinely accuse their targets of all sorts of heinous crimes; conspiracy, treason, plotting genocide, mass murder (trooferism?), sedition, etc.
It makes a real difference in terms of what the impressionable might regard as a justification for violence.