Yes, in this case, it isn't mere hyperbole to state that what they did was so evil, so treasonous, so treacherous, so damaging to the underpinnings of our constitutional republic, that nothing less than the death penalty would be an appropriate remedy.
The crime statute of Treason carries the death penalty.
Those subject to statutory treason are limited to those who took an Oath of Allegiance.
All government employees and elected office holders are sworn in under an Oath of Allegiance.