Overzealous event coordinators? A rare, unforced error committed by the Obama campaign's site advance teams.
From an article in the Tartan, the daily newspaper Carnegie Mellon University in Pittsburgh.
While the crowd was indeed diverse, some students at the event questioned the practices of Mrs. Obama's event coordinators, who handpicked the crowd sitting behind Mrs. Obama. The Tartan's correspondents observed one event coordinator say to another, "Get me more white people, we need more white people." To an Asian girl sitting in the back row, one coordinator said, "We're moving you, sorry. It's going to look so pretty, though."
"I didn't know they would say, 'We need a white person here," said attendee and senior psychology major Shayna Watson, who sat in the crowd behind Mrs. Obama. "I understood they would want a show of diversity, but to pick up people and to reseat them, I didn't know it would be so outright."