Le Meh. When you murder the head of the executive in a functional democracy, the system survives, because the system is more than the individual, no matter how powerful said individual is within the system.
The same is true of an old-school absolute monarchy, Rufus. When the king dies they make someone else the new king in his place.
That's why there is a peaceful transfer of power.
See above.
Even when there's no undisputed heir, after all the fighting is done the winner puts the same old crown on his head. The system survives. Democracy has no special claim on institutional stability.
OTOH, in autocratic systems, the leader is the system, usually as a feature because the infighting and dysfunction is encouraged to reinforce the individual power of said leader. So if you manage to kill them, the system is endangered or collapse entirely.
Which is why the Soviet Union imploded into civil war the moment Comrade Stalin was dead, huh?
Even in the case of freaking Nazi Germany, they responded to Hitler's death by making someone else the new
Fuhrer in his place - for the brief time they had left.
How is Le Strawman Autocracy at all relevant to the topic anyway?
Anyone educated in political science knows this, so killing the leader in a democracy isn't really productive for their opposition, reducing the plotters to small groups or individuals.
In addition to Le Strawman, you are basically pulling Le Goalpost-move.
Earlier you were claiming that killing an elected head-of-government would not change anything. Now it's that it would not cause the whole system to collapse?
If the people who are considering having their current president - or one of the candidates for the future one - bumped off, they are not trying to burn down the tree in which they themselves are sitting. They want to steer the ship, not sink it.
"If X is elected, he will do this-and-this-and-this, while if Y gets in he will do that-and-that-and-that"
"hmm... let's make sure that Y
doesn't get in!"
Is this so hard to follow?