Anyone else notice only Clinton has a firewall?

I was watching Ed Schultz tonight and something hit me as they were talking about South Carolina. Remember when Senator Sanders was doing better than expected in Iowa and New Hampshire and all the media was dismissing it because of Secretary Clinton's so-called minority "firewall?" Well why weren't they talking about the firewall Senator Sanders had with caucasian people? One can't be true without the other right? But this establishment bias has seeped into everything.