Obama's 2012 campaign headquarters (10 images)

Patrick McConville hops off a desk after hanging a sign at the Obama 2012 campaign headquarters in Chicago on May 12, 2011. The campaign recently occupied about 50,000 square feet of office space in the Prudential Building and held an open house Thursday for the media. UPI/Brian Kersey

Signs hang on a column at the Obama 2012 campaign headquarters in Chicago on May 12, 2011. The campaign rented about 50,000 square feet of office space in the Prudential Building and held an open house Thursday for the media. UPI/Brian Kersey

Volunteers and staffers work at the Obama 2012 campaign headquarters in Chicago on May 12, 2011. The campaign recently occupied about 50,000 square feet of office space in the Prudential Building and held an open house Thursday for the media. UPI/Brian Kersey

Joseph Tennial puts up a sign at the Obama 2012 campaign headquarters in Chicago on May 12, 2011. The campaign rented about 50,000 square feet of office space in the Prudential Building and held an open house Thursday for the media. UPI/Brian Kersey