There is a lot of this attitude ("Anyone who disagrees with me a stupid racist sexist Nazi POS!") on the Democratic side, unfortunately. (Let's not pretend that there isn't a similar attitude on the right, but I digress...) This is not a productive attitude, and it's certainly not going to serve any of us well in the future. While it's true that many Trump supporters are not going to be convinced to turn against him, there are certainly some who could potentially be swayed. The type of argument presented in this article is what has pushed many people away from the Democratic Party. Also, maybe convincing people in rural America to pull the lever in the voting booth a certain way shouldn't be our end goal. Perhaps empathy should be about recognizing that we don't have to see each other as enemies, rather than just winning elections.
I think the problem with the quest for empathy is that people are so deeply obsessed with "whataboutism" that we can't actually acknowledge that there are many different problems. Any human being wants their problems focused on first rather than someone else's, that much seems logical. The issue is that a lot of people fail to comprehend (whether that's our own failure as a society for not instilling that form of critical thinking or something else) that there are multiple problems that multiple groups of people are dealing with and that all of these should be addressed, not just one at a time and not just in piecemeal. A black man still probably going to be more socioeconomically disadvantaged for example than the median white man, and would probably have the cops called on him more often than the so-called "hillbilly", but they both have economic problems that must be handled. But the challenge is making everyone understand that everyone else has their own issues to deal with that are very complex and that nobody's problems are relatively speaking more special than anyone else's would probably be the biggest hurdle toward any kind of empathy.