If instead of in the case of red winning all blue voters die instantaneously, you had to kill them, you may use any method of your choice, you will not be legally punished, and some blue voters (or all) will have multiple people killing them bc it wouldnt be a 1:1 ratio (they would revive after dying) they will not be hard to kill, they will be teleported to you, tied to a chair with unbreakable wire. So what do you pick now?
First off, this is not meant to sway the minds of people who press the red button, but more so that they can see why some people might press the blue button.
I would not want to live in a world where red won for 2 main reasons (neither of them are because people who press red are assholes, I'd say that most red pressers aren't assholes, they just have reasons such as having families that rely on them, having lives that they don't want to risk, etc.):
A: I do think that red would win, but blue would have somewhere from 20% - 30% of the vote, which leads to my first reason, assuming that how it works is the effects of the vote happen instantaneously, then the world would quickly devolve into absolute chaos because 1.8 billion people (20% of the world) immediately dying will make a massive effect on the world, likely making it apocalyptic and just overall terrible to live in.
B: This is the more personal reason which is why I started off by saying that I'm not trying to sway the minds of the people. I know that the majority of my close friends and family would press the blue button, and if I survived and they didn't I would honestly rather just be dead, because I would have nothing to live for.