Trump knows he can't win a popular vote so he uses the divide method. It's basically a massive cult and he uses division to excite and infuriate his disciples into action. This worked well in 2016 where a high proportion of Americans are politically apathetic and don't even vote and he took the system by surprise. 4 years on, the division is greater than ever and I think if it wasn't for COVID19 and Trump's disastrous handling of it with incessant need to further divide than bring unity to fight it, Trump would have won again. Trump has become bolder and bolder, I can't imagine how he would have used his power with another 4 years. He's a loose cannon and very dangerous to give power to someone like him.
Republicans will reset without Trump and be better for it in the long run.