> Ergo polls are skewed to the right with error.

That's not necessarily the case. In the UK, there's a phenomenon known to pollsters as "shy tories": people who are too ashamed to admit to a pollster that they'll vote for the Nasty Party, let alone why. Then there's the case of my late mother-in-law, who would gleefully say "Of course I'll vote for you" to private pollsters from all parties, partly out of mischief (a party machine can always do with a bit of grit in its gears), but mainly to get them off her doorstep.

There's plenty of causes of slack in the figures, and they're somewhere on the border between "known unknowns" and "unknown unknowns". All poll figures are guesstimates at best, and sometimes outright wishful thinking. Ach, all we can say with certainty is that all of life is six to five against.