I Just Don't Understand

Trumpistas in 2016: “Sumner, you just don't understand. You professors live in an upper middle class bubble, where you don't see all the suffering out in the real America. The economy is not doing well; it's doing horribly. Things are so bad that average people are turning to meth, to opioids.” Trumpistas in 2018: “Sumner, you just don't understand. Trump has made America great again—the economy has never been better. Look at the stock market. Look at the black unemployment rate. As Trump says, America is doing great.” I'm willing to concede that I just don't understand, so please help me to learn.