It may interest you that the happiest nations in the world (overall and for a long time -> the Scandinavian countries) have the simplest form of democracy.

They have One House, and that's it. They use Thomas Jefferson's proportional voting system.

We?

We have One House, One Senate, and One Presidency, and we vote from among two parties. So, we vote three times in limiting manners and our three votes can end up fighting with one another (and do).

That means the Swedish voter has a lot more power with that one vote than we have with our three votes.

That is why they are happier than we are. They have We The People, and we have something watered down.