Explore "The Free Press" by Hilaire Belloc on Textopian. Read with annotations and highlights.
As to opinion, you have the same limitations.
If opinion can be once launched in spite of, or during the indifference of, the Press (and it is a big "if"); if there is no machinery for actually suppressing the mere statement of a doctrine clearly important to its readers -- then the Press is bound sooner or later to deal with such doctrine: just as it is bound to deal with really vital news.