Today we launch Part One in our series on pivotal moments in the lives of the 2020 presidential front-runners. In studio with “The Daily,” Pete Buttigieg, the mayor of South Bend, Ind., talks about how his lifelong political ambitions were complicated by the secret he kept for decades.Guests: Pete Buttigieg, mayor of South Bend, Ind., and 2020 Democratic presidential candidate.Jeremy W. Peters, a politics reporter in the Washington bureau of The New York Times.“The Candidates” is a new series from “The Daily” exploring pivotal moments in the lives of top presidential contenders in the 2020 election. For more information on today’s episode, visit nytimes.com/thedaily.