they are skewed to influence the outcome...."
What makes you think the polls, national or otherwise, are creditable?
These “polls” are meant to massage the “narrative”. If the polls are done at all, they are skewed to influence the outcome.
I will posit another notion. A news outlet commissions a poll. The pollster knows what the buyer wants and the trend to be shown, he waits a few days and draws up a data base from his files, re-jiggers the numbers and turns the completed poll in. Collects his fee and moves on to the next news outlet. This operation can be run out of a shoe-box. Who verifies that the pollster did the work.
I call BS on the whole polling scam, except for the internal polling and that is reflected in where campaigns are making appearances and the money injected into state campaigns, and maybe ad buys. Although, the time around, that may not be too good of an indicator.