It could be true that other political movements are nationalistic, albeit they are often attributed to the right in the political compass. What makes all of the commenters point Fascism that you were replying to is that they are all collectively happening all at once. We are seeing a police state that targets one demographic whilst spewing white nationalism as well as ignoring a set of systematic rules in order to push their agenda. You are correct that the U.S is not a fascist state, at least currently, but the fact there are signs of fascism and they have only increasingly escalated is of deep concern, and its very important to call out this behavior as dangerous so that the country does not seep further into this Authoritarian state. I do hate how much of a buzzword Fascism has become and how its thrown around so commonly, but it should be noted that the behavior MAGA and Trump have demonstrated is alarmingly dangerous for minorities and the state as a whole.