A former White House communications director for Donald Trump believes her old boss may back out of the Sept. 10 debate — and that Democrats are pining to debate with hot mics in hopes that he becomes “unhinged.” Alyssa Farah Griffin, former Trump White House communications director, spoke Monday night with CNN anchor Anderson Cooper on “Anderson Cooper 360°” and noted that Trump’s waffling on the debate shows how much the “calculation” has changed for Trump now that Kamala Harris is in the race instead of President Joe Biden. “Kamala Harris is a confident debater,” said Griffin. “A former pro…