I also notice the extreme desire of the left to create a left bubble. I often saw posts like "If you support ..., please unfollow me!". There even have been apps that allowed people who in their friend list followed some "extremists" like Trump. With a click you could unfriend all those people. So if you followed someone like Trump, you were already seen as an extremist yourself.
Doesn't it make sense to follow many people with a different opinion? If someone has the same opinion as me, why should I follow him? I already know my opinion. I want to know what people from the "other side" think.
In Germany a popular lawyer got attacked from the left for defending some right wing people. The same lawyer also had left wing clients. He said that everybody should have the right to get the best defence he can afford and that he will accept ANY client, because everybody is innocent until proven guilty. The left however really think that no lawyer should have any right wing clients and if you accept a right wing client, you are an extremist yourself.
Long ago I decided not to choose my friends based on political opinions and I will never end a friendship based on the political opinion of a friend. Sadly people from the left do that differently. If you do not share their opinion, your are the enemy. I therefore also like the word "leftists" for those people, as they remind me very much of islamists.
Doing boycotts of people with a different opinion is already very extreme. If you do a boycott and want others to do the same, you basically want to destroy the income of a person, so that he can no longer make a living from his job. In Germany we had a dark history of boycotting Jews before we treated them even worse.