I'm reading Harry Potter and the Order of the Phoenix (keeping my daughter company through the series) - this is the one in which Harry Potter and his associates know that Voldemort is back (Harry has seen him with his own eyes, been attacked by him); but the wizarding government and civil service and the 'mass media' (i.e. a newspaper called the Daily Prophet) deny the facts, label Potter at al as either crazy or evil, and interpret all evidence of Voldemort's increasing power in other ways - either ignoring them utterly, down-playing them, or re-interpreting them as the fault of HP and his associates.
This is helped by the fact that Voldemort is so feared that he is never specifically mentioned but is talked around as 'he who must not be named', or 'you know who'.
V is feared because he is powerful and relentless with a track record of near total domination; and because those who oppose him are so weak (and infiltrated) that defiance of the 'HWMNBN'd is more likely to be punished by officialdom than supported or assisted.
Because 'he' cannot be named or blamed, wizard bureaucracy is therefore primarily focused against dissident wizards who are named, blamed, and shamed; meanwhile Voledemort's most powerful supporters are allowed to escape from confinement (the prison guards have apparently changed sides and released them).
Then I survey the international media and Western government pronouncements on Google news and see that we live in the same world.
Interestingly, JK Rowling - although a professed Christian - is a very strong supporter of the British New Labour party and in her public pronouncements seems to be utterly captive to PC - which shows that she must be a good enough novelist to be able to write with deeper truthfulness than her aware and explicit convictions.