We are a country that is noted for, and is proud of, its peaceful transition of power. However, lately we have been living in bizarro land and there may be no going back from this. The new response to a both a democratically elected president, and unpopular speech, has been violence. The purpose of free speech in a free society is not to protect popular views, but to protect unpopular ones, because popular views need very little protection. We should recognize the right of people to protest peaceably, regardless of how much we disagree with their views.
Politically, we are in danger of becoming a third world country. In most places where people feel like they have very little political power, conspiracy theories run rampant; people believe that an external force or scapegoat is responsible for their oppression. So they riot in the streets.
The path we are on is a decline in civil society and a decline in civilization.
When Republicans lose, there is very little problem with the political transition. Republicans are used to losing and are used to being on the outside looking in, so they mostly have been content being the opposition party. Some people say that Republicans prefer to be the opposition party, as evidenced by their failure to lead.
However, there is an element in the extreme left that has risen up that is Marxist to the core. This element does not want to tolerate contrary opinions, because they view their opponents as oppressors, thus justifying a violent response. This is why we get calls for Trump's assassination, and actual violence.