Hillary Clinton has spoken at the Democratic National Convention of her hope that Kamala Harris can finally break the “highest, hardest glass ceiling” in America by becoming the first female president. Ms Clinton said she had broken a glass ceiling of her own by becoming the first woman to win a major party nomination for president. “When a barrier falls for one of us, it clears the way for all of us,” she said, echoing her convention speech from eight years before. But while her bid...