 On June 27th, Biden has made it plain that he will not yield. In his post-debate push to prove he's cogent and competent, Biden has at times stoked concerns about both. In a few hours on Thursday, he referred to Ukrainian President Volodymyr Zelensky as President Putin and his Vice President Kamala Harris as Vice President Trump. A new national NBC News poll, by the way, finds that more than 60% of Democrats say they'd prefer someone else at the top of the ticket.