LAS VEGAS, NV — It is well known that you should never stand between a blogger and a free lunch, but at NetRoots Nation, all rules get thrown out the window if you’re doing it for a cause. In a stunt by Los Angeles-based immigration activists, three men wearing homemade Immigration and Customs Enforcement uniforms guarded the door to the lunchroom at the liberal political conference Friday, demanding that all white attendees show their “papers” before entering. “All North European immigrants or people of European background must show ID,” shouted activist Will Coley as he stood in front of the...