Read this: North Carolina's party loyalties have undergone a series of important shifts in the last few years: While the 2010 midterms saw Tar Heel voters elect a bicameral Republican majority legislature for the first time in over a century, North Carolina has also become a Southern swing state in presidential races. Since Southern Democrat Jimmy Carter's comfortable victory in the state in 1976, the state had consistently leaned Republican in presidential elections until Democrat Barack Obama narrowly won the state in 2008. In the 1990s, Democrat Bill Clinton came within a point of winning the state in 1992 and also only narrowly lost the state in 1996. In the early 2000s, Republican George W. Bush easily won the state by over 12 points, but by 2008, demographic shifts, population growth, and increased liberalization in heavily populated areas such as the Research Triangle, Charlotte, Greensboro, Winston-Salem, Fayetteville, and Asheville, propelled Barack Obama to victory in North Carolina, the first Democrat to win the state since 1976. In 2012, North Carolina was again considered a competitive swing state, with the Democrats even holding their 2012 Democratic National Convention in Charlotte. However, Republican Mitt Romney ultimately eked out a 2-point win in North Carolina, the only 2012 swing state that Obama lost, and one of only two states (along with Indiana) to flip from Obama in 2008 to the GOP in 2012.

Where was the 2012 democratic national Convention held?
What is the answer? (If it cannot be answered, return "unanswerable")
Charlotte