I'm looking for a comprehensive as can be book or short series about the US presidents, from #1 up to and including Obama, but not necessarily, since I understand he's not quite history yet, just a few short months removed from office. While I understand it would take a doctoral degree, involving reading dozens of books, primary sources etc to have a complete understanding of each president, I'm looking for something that's a bit easier to digest. Whether it's a single book or a short series, I'm looking for something in the order of several hundred to a couple thousand pages.

To clarify, I'm most interested in their political careers, much moreso than their personal lives, though that is definitely a requirement as well. I don't want to read trimmed-down biographies of these people, detailing how they grew up etc. I want to understand how their administrations worked, what challenges they faced, what they accomplished, I want that to be the meat of the book, while of course also getting personal information to contextualize it all.

To end a rather long-winded post, I'm not interested in reading about presidents from a conservative/liberal point of view. Though I'm as liberal as they come, I don't believe that's a good way to learn about history. I'm definitely looking for something with a more neutral perspective, though some author analysis is certainly welcome if it's along the established thinking.

And lastly, as far as reading level, I actually was a history major so I don't necessarily have a problem reading scholarly work. I specialized in roman history (wrote my thesis on Constantine's "conversion" to Christianity), so I just didn't get the time to focus on US politics. Anyway, while I'm not scared of that kind of dense reading, of course i'm open to lighter, coffee-table sort of reading as well, or anything in the middle.

EDIT: I'm bad at math and made a fatal error. Obviously I need more of an anthology vs one or two books.