SOUTH BEND, Ind. — Democrat Pete Buttigieg, the 37-year-old mayor of South Bend, Indiana, says he’s forming an exploratory committee for a 2020 presidential bid. “The reality is there’s no going back, and there’s no such thing as ‘again’ in the real world. We can’t look for greatness in the past,” Buttigieg says in a video that includes before-and-after footage of South Bend, a Rust Belt city once described as “dying.” “Right now our country needs a fresh start,” he says.