Before Jack's speech it's possible that one or two people could have noticed Charlie straightening Jack's tie "offstage" aka behind a tree or some shrubbery which in and of itself isn't THAT STRANGE (she has been picking his clothing ever since the campaign started) but anyone who slipped by close enough might have noticed that Jack was standing comfortably close to Charlie. He had a puppy love look to his face, and even whispered a few things in Charlie's ear that made her laugh and shove him away a little.