Certainly Googlebot can read it. The question is rather, "Will they see it as spam?" You can see how hidden divs could be used as a spamming technique. There is a thread going on in Google News about CSS and spam, particularly whether Google dislike absolute positioning.
I think its clear there must be a lot of wiggle room for CSS, but this is something of an extreme case. Google is going to wonder why 95% of the page's content is invisible!
You might also note how wasteful the scheme is. If someone arrives at a tiny page, but it takes forever to load, they are going to perceive (subconsciously or not) that the sponsoring organization is incompetent or irritating.