> This is why the swing voters / swing states are so important in the US, because only a few million are flexible enough to switch sides.

Of course if the USA was an actual democracy, electing it's president by popular vote, then this would not be an issue - every vote would count to tip the balance in favor of who the people wanted to elect, not just the votes of the 20% fortunate enough to live in a "swing" state.

> A lot of votes vote one way or the other because they would simply never vote for the other.

This, for me, is the crux. Politics is treated like a team sport in the US, you pick your side and cheer them on no matter what. And team sports in America are even more bananas - you grow up supporting the Brooklyn Dodgers and a few years later they're 2.5k miles away with a new name. This seems a perfect example of what's happened / happening to the Republican Party - it's not the same party any more, but everyone who tied their entire personality to cheering for the red team is still cheering for it as it burns the country to the ground. I predict that inside ten years it will have also had the name change and probably be run out of Florida or somewhere.

Parliamentary systems with more coalition involved instead of two party first-past-the-post can foster extremes too, like we're seeing in Israel.