There's an axiom in polling that goes back to 1936. If you expect to win the presidency, you'd better be polling well as September begins.
Nobody really 'likes' to admit that polling is as good of a science as it is; it tends to undermine our sense of control and autonomy -- that less than 1,000 people polled can represent the population of 146 million or so voters in the United States.
But that's the nature of statistics -- as well as the numbers being criticized for any number of reasons.