The acid test for political bias is simple: Does the passage in question reflect what the reliable sources say? Does it reflect a consensus among the reliable sources? Does it reflect a very significant minority of the reliable sources?
If it does, the assumption should be that the passage should go into the article. There will be complications: Wikipedia Biographies of Living Persons policy may still nix inclusion of the passage in Wikipedia. Other policies may put roadblocks in the way. But overall, in most disputes, bias is shown when editors are advocating (or have added to an article) information that does not reflect what the reliable sources say.
Even [[WP:BLP]] policy, when dealing with [[WP:WELLKNOWN]] public figures, depends on reliable sources: If reliable sources criticize a WP:WELLKNOWN person, the information should be included in an article on that person or, depending on relevance, on the subject.
