The closest example I can think of for people avoiding a car brand for political reasons is "Greatest Generation"/Boomers refusing to buy cars from Honda, Toyota and other Japanese companies because of Pearl Harbor, but most of them relented eventually because the value of Japanese cars was undeniably better.

This is not to say that Tesla won't suffer for Musk-induced political reasons. But I don't think this is the primary mechanism behind Tesla's downfall. Rather, I think Musk's political flailing has punctured his reality distortion bubble, so Tesla is returning to the value it rationally should have been at the whole time. It has always been a fringe manufacturer, propped up by unrealistic fantasy about the near future.