The author is clearly not a big fan of Margaret Thatcher and the various members of her cabinet. Compared to them, Enoch Powell — who is himself not exactly favourably depicted — is a model human being (oddly enough, the author would also later serve as a Conservative Party councillor).
The Northern Irish Unionists are universally depicted as monsters with them actively waging a campaign of ethnic cleansing against Catholics by way of death squads, rape, torture and lynching. Also the British as a whole are depicted as being insanely racist, anti catholic and anti Irish.
Alternate History Wank: It is hard to escape the feeling that the hatred shown to the tories, unionists, and often the British in general through their portrayal as near caricatured psychopaths, as well as the utter humiliation each go through by the end of the story is not some form of wish fulfillment
Fridge Logic: In the end it is implied that because of the actions of Powell's regime, Britain became and remained a Pariah state and despised by the world for well after 20 years had passed. Given that real world nations such as Spain, South Africa, Argentina, Most Warsaw Pact nations, the Soviet Union, China and dozens of other nations had far more lengthy and far more brutal regimes than the one depicted as occurring in Britain, it seems strange that Britain alone would be singled out and despised above all others.