One time the polls will come in handy, in my opinion, is on election day itself when Trump loses and says it’s because the election was rigged. And you just know the R-word will be the first one out of his oval orifice.
If he’s ahead in the polls and he loses, he’ll have at least some credibility.
But if he’s behind in the polls and he loses, it will be just one more instance of denial without any foundation.