Only half of people even vote but enough people are going to be motivated to take up arms against each other? Rrrrrriiiiiggggghhhhhttttt.
Things are WAY too good here to so motivate people.
Before I respond to your point, I will say that I personally do not think we are close to a civil war. Are we close to being in a more violent time where more domestic terrorism occurs? Sure. But an actual organised shooting war for territory? Absolutely not.
Having said that, it doesn’t take THAT many people to start a true civil war. The Revolutionary War was a true civil war and it had roughly 20% of the military aged men on the side of the rebels/“Patriots”, about 15% were Loyalists who sided or fought for the Crown and the other 65% were fencesitters who simply didn’t want to get shot.