After much effort and struggles with copyeditors (don't get him started), Professor Sousa and his co-author, Professor Christopher Klyza (Middlebury) have just released
American Environmental Policy, 1990-2006: Beyond Gridlock through MIT press. Pre-released it, anyway; it's due to come out at the end of the year, but you can preorder your copy on Amazon
now. And the reviews:
"Quite simply, this is the best book on environmental politics and American politics I have read in some time."
Congratulations to Professor Sousa for this important accomplishment.