Aruntraveller linked to this in #629, and I replied to it. Trump is not an ideologue, and I don't think that makes him less dangerous but more so. But using the term fascist here is dangerous as well, as it will be heard on the minds of swithering voters as calling them fascist. The polarisation is politics is in part driven by the lazy use of such rhetoric.
In "How Fascism Works" Jason Stanley wrote the following:
[A] cult of the leader who promises national restoration in the face of humiliation brought on by supposed communists, Marxists and minorities and immigrants who are supposedly posing a threat to the character and the history of a nation ... The leader proposes that only he can solve it and all of his political opponents are enemies or traitors.
Now that would seem to be a fair description of many of Trump's characteristics and rhetorical style. But I would agree with you that it would be very difficult to call Trump an idealogue, since his his sole raison d'etre is about his own precious self, and is just using a Republican platform as a convenient means to this end. Any lie, any inflammatory statement to fire up his 'enthusiasts', any pretended religious sympathies (in which he doesn't believe) are grist to his mill - the glorification of his egregious narcissism and unlimited lust for power. Nietzsche is still our best teacher here. The astonishing thing for me as that so many Republicans - who can't all be so thick or insane as Marjorie Taylor Greene* - are prepared to swallow all this. Perhaps it's because one remarkable thing about Trump is his capacity to lie and lie with such ineluctable energy, when most people would have simply backed down. And therefore his supporters think he must be telling the truth. (Putin of course has a similar capacity).
*Marjorie Taylor Greene, by contrast, is an idealogue. But so batshit crazy, she's always good for a laugh.