Great comment, especially the last part, RIP TK. The key to reading this book is setting aside comfortable filters (or fallback positions) and really thinking about what's being said. Talking with people I know about the subjects Dennis wrote on, it surprises me how many of them leap to counterarguments only to demonstrate with further discussion that they don't really understand the positions they oppose (and quickly take offense to).
I recently gave a left leaning guy I work with who keeps up with all the news and current events, and who is in favor of gay marriage a great article explaining conservative opposition to it and asked him if he'd ever read or heard those points before. He never had. If there's one thing that GREATLY helps fight that, it's clear articulation of the big ideas followed by solid examples. This book provides that. I hope it gets a LOT of readers!