Look up Christopher Hitchen's lecture on how Saddam Hussein consolidated power in his Baathist purge of ~1979.

Step 1: Randomly select a large portion of the assembled party as enemies of the state / party.

Step 2: Enlist the remaining party members to execute the first.

Step 3: ???

Step 4: Profit!

It's a formula even more twisted than Hitler and Stalin.

Nine minutes: https://youtu.be/CR1X3zV6X5Y