Actually, I think Bush and the GOP stripped out the stuff that would have covered right wingnuts, but it was reinstated by the "do nothing" Dems Congress.
Insurrection Act - Wikipedia, the free encyclopedia
Maybe someone can read further and translate...sort of complicated, but Bush definitely changed it from:
insurrection, domestic violence, unlawful combination, or conspiracy
to:
natural disaster, epidemic, or other serious public health emergency, terrorist attack or incident, or other condition
there must be a reason he removed a lot of the text - but a moot point now, since his thing was overturned.