He certainly bears some of the blame. All politicians vigorously attack their opponents. But if I’m not mistaken, Obama was the first U.S. president to widely and frequently disrespect the voter. Remember his rallies where he would surround himself with people, laugh at and belittle people who have different opinions than him? Then he accused us of bitterly clinging to our guns and religion. Then Hillary doubled down on it with her horrific deplorables list. Now Biden seems to be grabbing the torch as well.
What about Trump you ask? Does Trump go over the top with his insults? Yes he does. Should he dial it back? Again yes. Does he get some blame? Of course. Much of it. But Trump typically goes after people who have gone after him. You do not need to prove to me that he has been out of line at times. I get it.
But. He certainly does not get all of the blame. Obama is the grandfather of unprovoked insults on the voter. No doubt about that.