Former President Donald Trump and his supporters, faced with a tougher election now that Vice President Kamala Harris has stepped in as the nominee, have taken to claiming that the replacement of President Joe Biden from the ticket is a “coup,” or even that it could be “unconstitutional” and invalid on state ballots. But this is nonsense, former federal prosecutor and CNN legal commentator Jeffrey Toobin told Anderson Cooper on Thursday. “So is there any legal footing for this argument that it was unconstitutional for Harris to become the nominee?” asked Cooper. Want more breaking political ne…