If Trump were to be reelected and went on a purge of similar bloodiness per capita to the Dirty War in Pinochet's junta in Argentina, that would mean ~350,000 dead Americans.
trump has publicly stated his desire to deport something on the order of 20 million people, if 2% of the deportees died in the process the death toll would exceed 350,000
Very possible. I would hit migrants or other vulnerable outgroups first. I would break humanitarian norms to provide information on private loyalties within the security services. This would allow me to sideline officials that might oppose me.
After that, I'd turn my loyalists on other enemies.