On the eve of Supreme Court oral arguments in the Wisconsin gerrymandering case of Gill v. Whitford, two national experts join the "Mean" to break it all down. FairVote Executive Director Rob Richie explains why over 90% of U.S. House incumbents win re-election - and what can be done to unrig our congressional races. Then Univ. of Chicago legal scholar Nick Stephanopoulos talks about how his "Efficiency Gap" measurement could be the key to the Supreme Court making a historic decision on gerrymandering.