It was my week to post on the 6th Cir. blog, so here's a link to my discussion of United States v. Bistline, No. 10-3106 (6th Cir. Jan. 9, 2012) (for publication).
Congressional involvement in the GLs and political (rather than empirical) motivation for GLs not valid reasons to reject GLs.
www.circuit6.blogspot.com.