And what a review it is. The whole post is worth a close reading, but here are the highlights:

Readability/quality: Concise, persuasive and methodically documented, Over the Cliff is a smooth and sobering read. It feels much shorter than it actually is—there’s a lot of information packed in, both historical and current, and a tremendous job has been done in picking through the right-wing landscape for pertinent, on-the-money examples. Lord knows you could spend a couple thousand pages just on documenting the day-to-day rhetoric (in fact, Media Matters does just that). So thanks, guys, for paring it down and honing it.

Who should read it: Everybody. Seriously. This is a wake-up call for those in denial, a refresher course for the painfully aware. Good reference to have on hand in your permanent home library for quick examples of extremism in Obama’s first year.

And a sobering conclusion:

Beware. There’s even more crazy in front of us than behind, the authors say.