On Thursday, disgraced political analyst turned Newsmax commentator Mark Halperin laid out in exquisite detail what he claimed was reporting about how President Joe Biden is planning to announce the end of his presidential run imminently. But one portion of that reporting, that historian and speechwriter Jon Meacham is crafting an exit speech, has now been debunked by the man himself. “Historian Jon Meacham to me just now via text: ‘the report about my doing anything with a speech is totally false,'” reported CBS chief election correspondent Robert Costa on X. “Comes as Meacham is being talked…