A bit of an oxymoron, isn't it, killing a democratic leader.

By virtue of democracy, sort of a built in mechanism, there isn't a need to kill their leader. A democracy has checks and balances to ensure authoritarianism is not allowed, partly by not allowing consolidation of power into one office.

So if you feel the need to kill your leader, chances are you're either mentally ill or not in a democracy.

Probably the former.