Let's begin by saying that we can disagree without flinging hate around. ALL of us. We are capable of it.
When I was a kid, discussing politics with friends, neighbors, and family was common. Although occasionally the discussion would get heated, nobody died, was assaulted, or even refused to speak to each other ever again.
That changed in the 1960's - and I'm ashamed to say, that although I was not one who shouted down speakers, I did little to stop those who did. That's really when the politics of hate began (at least, in public).
It's an Alinksy tactic (and, before, a tactic of the Communist Left - the Old Left).
If you don't know Alinsky, I suggest that you learn more about him, He is the man that developed most of the strategies of the current Left, and a hero to Hillary Clinton (she was offered a job with him after graduation from law school).
CORRECTION to the above - she was offered a job with Alinsky BEFORE law school.
Alinsky also had a pernicious effect on the Catholic Left, although few in that group know it.
For more information about the Alinsky Effect, go to this link.