What are some good books to read to understand the "living constitution" and judicial activist theories?

I am currently in law school, and have been interested in jurisprudencial issues for a while. I am decidedly originalist, but I want to try to get a better understanding of other theories. I tried to read Justice Brennen's "Active Liberty," but I found his writing style increadably grating and couldn't properly focus on the ideas he was expounding. Any ideas on what I should read?