As Democratic presidential hopeful Kamala Harris vets potential running mates, spare a thought for the contenders as they undergo a process that one past participant likens to "a colonoscopy performed with a telescope”. Have you ever paid for sex? Have you ever paid for an abortion? Have you ever had a homosexual encounter? This is just some of the material in questionnaires fired off during the exhaustive vetting process for previous US vice-presidential nominees. Potential partners to join Ms Harris on the Democratic ticket for November's election will have to answer up to 200 questions before they can even begin...