Antagonist: If my ideology is enacted, everything will be better!
Liberal Protagonists: oh fuck how will we deal with this, I have no arguments to defend the status quo
Antagonist: just kidding, all that ideology was a trick, I'm Just Evil™
And then they can kill him without thinking about anything at all. Happens all the time.
Off the top of my head is legend of korra (I know im 2 weeks late for that discourse) the Black Panther movie, and even Pokemon Black/White have the same themes
I think a lot of the time it goes like
Antagonist: If my ideology is enacted, everything will be better!
Protagonist: oh fuck how will we deal with this, I have no arguments to defend the status quo
Antagonist: And also, for some reason, I'm going to murder a bunch of innocent people in a way that doesn't even really further my objectives
Protagonist: Killing people is bad! I will strike you down