It's hard because, yes you are right, but when can you start calling somone a fascist? Do you have have to wait for them to actually start rounding you up and putting you in prison, or can you point it out early in order to avoid the complete fascist takeover?
I guess my point is that, once a group is actually fully fascist, you will no longer be allowed to call them that.
Not saying that you're wrong per se, but where would you put Trump in this context? They are very well going in this direction.. And they are not turning back.
I think Trump has some of the fascist traits Eco points out, like xenophobia and appealing to a frustrated middle class. But he is thoroughly lacking in other fascist traits, like (1) the syncretic neo-pagan mysticism and (2) the idea that the state should always be at war, that the state should encourage all citizens to die a hero's death.
So I'd call him authoritarian, christian nationalist, and stupid. But not fascist.