evidence: Since becoming the presumptive Democratic candidate for president, Vice President Kamala Harris has done myriad public appearances and given speeches. She will give her biggest one yet when she formally accepts the nomination Thursday night at the Democratic National Convention. But she has not, as of this writing, talked to journalists outside a brief session on the tarmac before a flight. [...] Because of her refusal to sit for an interview with any print or broadcast media, Harris has been the target of a lot of indignant insistence that she change her mind — that she’s not giving the American public answers they deserve. Critics say she’s subverting an expected system that all other elected officials have gone through. They say she’s hiding behind a wall of hype and "irrational exuberance" that is proof she lacks the toughness to hold the office she seeks.