Ben Carson, possible 2016 presidential candidate, listens to a question during an interview during the Conservative Political Action Conference (CPAC) in National Harbor, Maryland, U.S., on Thursday, Feb. 26, 2015. The 42nd annual CPAC, which runs until Feb. 28, features most of the potential Republican candidates for president, from Carson and Carly Fiorina to Jeb Bush and Scott Walker. Photographer: Andrew Harrer/Bloomberg via Getty Images
