Troubadour, you have funny ideas about polling!
The sample is not self selected!

A large random cross section of the population is surveyed for their views.
It is how public opinion is assessed by government and by industry and commerce.
If the results were meaningless, vast sums would not be spent on them.
If different polls show similar results, it is a powerful indication that they are correct.
That is what we find here, with no poll showing any serious variation.

If you reject that hard evidence, you are just in denial.
Musket was wrong, and all you so desperate to support his false claim are also wrong.
Sorry.