there is no such "prejudice" or "superior"/"inferior" ideas in the above poem

Don't be ridiculous. You quite clearly say that 'mass immigration' (by non-English people) has led to the partial loss of English culture. You go so far as to equate the defence of English culture against the influence of non-English immigrants with the defence of liberty against Fascism.

OED: "prejudice and antagonism towards people of other races, especially those felt to be a threat to one's cultural or racial integrity or economic well-being"

The definition fits like a glove.