If there is such a conspiracy at the top of the justice system of the US, it is unlikely the coup plotters can be purged by the system itself. They will move against the President and elected government with support from almost all of the Democrats and many GOPe infiltrators. Trump seems to be checkmated in any attempt to stop Mueller and the DOJ from within the system. Other mass actions will have to be considered, the military, millions marching on DC if Trump is impeached, or other innovative alt4ernatives, whatever they may be.
If that were to happen, I hope the POTUS could rely on the men of the USMC to protect our country from its domestic enemies. It hasn't come to that yet, but we may be heading towards it.