Harry Potter is distinctly about protecting the "sanctity" of institutions, at the expense of individuality. Umbridge may be the personification of bureaucracy

Harry Potter is distinctly about protecting the "sanctity" of institutions, at the expense of individuality. Umbridge may be the personification of bureaucracy in our minds, but in JKR's, she's a threat to the image of British boarding schools being elite, character-building places for children. Note that, as a disciplinarian, she's functionally equivalent to Snape. That was not Umbridge's "sin". Her sin was teaching to the test, removing the academic rigor of Hogwarts, presumably leaving it on par with lesser schools. We might even look at her clothing and, in our minds, it looks very conservative. But in the wizard world, we never see anyone wearing such outlandishly colorful clothing. What looks like a makeup MLM saleswoman's outfit to us is a radical expression of individual style in the HP world. In Harry Potter, individuality comes at a price. The more you express individualistic thought, living outside of the norms of society, the more impoverished you need to be to remain "good". Look at the Weasleys. Look at the Lovegoods. Those that attempt to be successful and individuals are default evil. HP is so incredibly conservative, it's surprising everyone was surprised by JKR's politics.