Commonly accepted, but untrue in Presidential elections.
Well, I am certainly open to persuasion but I would merely note that if what you mean is that undecided voters in May do not necessarily end up breaking for the challenger in November then I certainly don't disagree. However, my original statement was an 'if the election were held today' statement. I haven't made any prediction whatsoever about what I think will happen in November if for no other reason than because I haven't decided yet.