TRAITOR DON turns out to be a LYNCHPIN without which the insurrectionists would have had no guidance no direction no cohesion. Agree?.

I asked and an Anssermugger friend suggests that. Without the lynchpin it would not LIKELY have happened. The insurrection being the "it" here. Which puts enormous power in one tiny little part doesn't it?

LINCHPIN/LYNCHPIN
"Something that holds a complicated structure together"