How to find the balance between research and the obvious
I'm embarking on writing my first popular science book on a controversial subject. For sure the writing must be rational, coherent with a clear train of thought and littered with references to be convincing. On the other hand, too much of that and the book will be all but "popular."
What I chose to call the obvious is the narrative, the self-evident and prevalent theories about connections with other fields of science. To me as a reader, this is usually the good parts as long as they're well supported by the research bits.
Many scientists write very defensively to "cover all the bases," but to me that style of writing is boring with a pinch of gutlessness and I really want to avoid falling into that trap. Especially as I'll in the coming months will spend countless hours reading books and articles, and I have a strong feeling that the tone of writing is contagious.
Most importantly I do want to write for people who are not very technical or familiar with scientific literature. So while the subject is controversial and thus requires some number-juggling, the style in many ways needs to be obvious.
So how to strike a balance between the two? Can you think of any rule of thumb or perhaps even a successful example of such a book? I realize asking "how much fact is too much" is impossible to answer, but I'm thankful for any guidance I can get.