When has assassination ever accomplished what the assassin wanted? Most successful political movements, at least in recent history, do not involve killing anybody.
With higher profile assassinations, the results seem to be less predictable. But I think we tend to ignore all the smaller assassinations that gave just the right edge to the opposition since those people just fade into the background noise.
Do you have an example? If you're talking about government-sponsored assassinations, I think that's less relevant, we're talking about how "normal" people can influence politicians.
The assassination of JFK & RFK put Johnson into power. Power mongers pulled all kinds of schemes from there. The assassination of MLK per testimony in court case was intended to stop overthrow of U.S. government by masses tired of their shit. That didn't happen. Numerous witnesses to various things in intelligence misconduct never lived to say it in court. Those things are still debatable due to missing information. And so on.
Assassinations that have worked so far were done by the power establishment to expand or protect its power. They tend to work. They're rarely needed, though, as they can do things like media spins, disenfranchising voters, regular arrests, and so on.
As I said in another comment, this thread was about how average people could influence politicians. Government-sponsored assassinations are a different discussion.
Assassinating the most corrupt officials on a regular basis could have similar influence. They'd know they could pull schemes for money but would die past a certain point of damage to the people or elimination of their end of constitution. It works similarly.
It would just be harder as they'd have (a) lots more security, (b) most police going after whoever killed them while simultaneously ignoring whatever the politicians were doing, and (c) media protecting them since corruption works to media owners' benefit as well.
Your first sentence assumes we know the assassins' motives. I question that.
Your second sentence assumes that any assassinations would be publicly known (eg assassination of a public figure). Assassination of non-public figures may well be impactful and yet go largely unheeded.
