In addition to my previous article (On Kitsch) just a few more (by no means exhaustive) thoughts on this topic:
It seems to me that ideological thinking is characterized by the absence of reflection. With reflection I mean the presence of a meta-level of thinking from which thoughts (including thoughts on that meta-level itself) can be critically reviewed and also changed.
In a previous article (Reflexivity and Creativity) I have hinted at the close connection I see between reflexivity and creativity. In ideological thinking, reflection is blocked, leading to stagnation of thought. Certain ideas are made dogmas by disallowing reflection on them.
In art, the absence of reflection generates kitsch. The creative process stagnates. The result is dull pseudo-art. Certain forms might also acquire a status comparable to the dogmas of ideologies. Art that does not conform to these forms is then perceived as aberrant.