Why do people despise so many of our presidents.?

American politics have become extremely polarized, creating a very deep "us v. them" mentality. This is aided by the harsh political rhetoric that is commonly used by today's political commentators. The result is the perception that the other side can't possibly be correct about anything. Furthermore, research shows that the people who are typically the most vocal in the political arena are the ones that are the most extreme in their views, so the perception is that the nation is much more divided than it actually is.