To be fair, I thought the point of an editorial was for the author to express their opinion. [1]
[1] From dictionary.com: 'Editorial definition, an article in a newspaper or other periodical or on a website presenting the opinion of the publisher, writer, or editor'
I think the difference would be a paper that features editorials which present a diversity of views versus one that seems to editorialize consistently in support of a particular ideology.
[1] From dictionary.com: 'Editorial definition, an article in a newspaper or other periodical or on a website presenting the opinion of the publisher, writer, or editor'