Andrew, Although not a wiki expert, I believe that emails/memos and letters from official sources (e.g. a local council member) discussing the issue would provide a suitable enough reference. Check out wikiepdia's manual of style for guidance on quotations. You might also consider changing the article to something along the lines of "It was reported at the time that Taylor was disliked in his local constituency because of his colour. These reports were used to sensationalise the election and are largely unsupportable." There are ways of saying almost what you want. All the best