evidence: Joe Biden’s decision to drop out and endorse Kamala Harris to succeed him on the Democratic ticket has Donald Trump’s team scrambling. [...] Much of Donald Trump’s presidential campaign, including the decision to tap Ohio Senator J.D. Vance as his running mate, was structured around attacks on President Joe Biden. But then Biden announced Sunday that he was withdrawing from the presidential race altogether. [...] Trump decried Biden’s decision to drop out in a post on Truth Social, writing that his team would have to "start all over again" and asking to be reimbursed for the cost. At the same time, Vance has set straight to work, calling for Biden to resign from the presidency.