CONCORD, New Hampshire — Bernie Sanders said at a forum in New Hampshire that women still face obstacles when they run for office, describing being a woman as a potential “problem” and noting that anyone who runs for office “brings some negatives” when it comes to appealing to the American electorate. The language instantly re-opened a conflict between supporters of Elizabeth Warren and Sanders over questions about electability, gender, and a private conversation between the two senators where they discussed whether a woman can win in 2020. “Everybody has their own sets of problems,” Sanders said during a forum sponsored...