I'd argue that rigging an election/attempting to rig a presidential election is more serious than the death of a single American. I don't have an exact number in mind that tops the act of rigging an election. I would characterize interfering with electoral processes to be an act of war.
I would also suggest that perpetrating attacks on critical infrastructure is possibly more serious.
A single American? Our people have attributed over 600 American deaths in Iraq to this guy's militias over the years.... and many multiples of that had been maimed.... he was the king of the IED.