I did a podcast yesterday with Steve Hayward on his latest book--I think he has a new book every three months!--The Politically Incorrect Guide to the Presidents: From Wilson to Obama. After having taught at AU this past fall, Steve appears to have gotten carried away with assigning grades, as he uses this book to give each president from Wilson to Obama a letter grade based on their support of the Constitution during their term in office. It's an interesting exercise, though, and he explains in the podcast what criteria he used.
Steve and I had a great conversation on his book and other things. Take a listen if you have some time -- it's only a little over 15 minutes long.