Well, I have seen a rise in left politics going overboard.
But lets share the blame here, the right wing has always been over the top with crazy, and these days they are loud and proud with it.
The left and right have their share of crazies... The media likes to divide and cover the extreme stories.. Most people I know are pretty reasonable.. Though I will say the people I have seen go off the rails during a discussion tend to be Left leaning.. They are still my friends but people don't discuss politics with them because they cant handle it.
My more extreme Right leaning friends seem to have more of a sense of humor about it all even though I have had a heated discussion or two with them about Trump... But they never storm off or try and yell others down.
But that is just my experience.. I do believe the media likes to act like the county is more divided then it is. I guess if you go online you will find the worst of the worst. That's why I don't have a twitter account.. I cant even imagine reading that crap on a daily basis.