The U.S.A. recently had another birthday, its 244th, if you begin counting with the Declaration of Independence. The people living here then didn’t think of themselves as a single nation, but the union they formed has been around long enough for everyone to assume this wild democratic experiment is going to work.

In 2020, it’s hard to imagine a world without democracy, although it’s a relatively new thing for a country to exist without a king or queen (usually a king) to make ru...