Is this the biggest mass mental breakdown in the history of our country?
Totally predictable. If anyone with a brain wants to read about narcissism you would know exactly how Trump was going to deal with losing. No one should expect him to concede. No one should expect him to handle the transition like a mature adult and do the right thing for the American people.
What Trump is going to do is basically quit being President privately because there is nothing in it for him anymore. Publicly he will continue to contest the results of the election without evidence because he wants to believe there was cheating. As long as he believes that himself he can avoid deflating his grand images of his self.
Biden voters need to understand this because if you keep expecting him to behave like he is a mature and reasonable adult with strong emotional intelligence you're going to keep being outraged. He is not that person, never was, and most likely at 74 years old never will be.
Trump voters need to understand that his questioning of election results has no basis in reality and is in fact a narcissistic coping mechanism to avoid self evaluation after a failure.
None of us like to fail but most of us as we age and mature learn to view failure as a learning experience. We admit our role in the failure and analyze what we could do next time to succeed and then work on that. Narcissists think they are perfect. To fail punctures this image so failure is impossible to admit for them. Thus they do things like accuse people of cheating, act like they don't care or didn't try, allege fraud, and create conspiracies aligned against themselves to avoid identifying their role in failure. When a narcissist fails instead of admitting failure they twist the situation to become a victim instead.
As we all view the next 70ish days watch the situation through that spectrum. When you understand what a narcissist is and how they behave and admit that Trump is a classic example of one, his behavior is predictable and expected. As such do not expect a concession, do not expect him to be at Biden's inauguration, and do expect him to continue to use his leverage to undermine Biden. In Trump's inner mind Biden has humiliated him publicly and he now views himself as a victim so his energy will be spent undermining Biden probably for the rest of his life. If Trump starts holding rallies again, do not be surprised if there are subtle threats and hints of violence toward Biden and his staff.