>There's value in having speedbumps that keep 51%* of the population from shooting 100% (or 99%) of the population in the collective foot... or in this case, head.

That metaphor breaks down here and is not really applicable. If two people are chained to each other at the ankles, they can both plausibly argue that the only way to save their own life is to take that of the other person. Whining "but I'm the good guy, I deserve to cut off his foot and let him be the one to bleed to death" is asinine.

The solution here is, of course, to not be chained to the other person irreversibly. But any time that is suggested, we hear a bunch of "We're stronger together, that's crazy talk!" And here we are. 330 million people all chained together, and now people are upset that the other team has the hatchets and is menacingly staring at their ankles.

>and another significant percentage of the population is not yet old enough to vote

Not sensible enough to vote. Don't leave that part out.

This isn't 1861, sectionalism isn't strong enough. One part of what's going on here is cities at odds with the countryside, another part is the internet, smartphones, ubiquitous connectivity, filter bubbles. People are physically present in the same locations but they are not eating the same bread and drinking the same water, metaphorically speaking. I recommend looking at this Wikipedia article for a possible best-case scenario: https://en.wikipedia.org/wiki/Population_exchange_between_Gr...