Are the polls skewed?

[Torie]

Here is the problem. Cell phone folks, and persons of color and so forth don't answer the phone as much as old white females (yes women answer the phone more). So you have to re-weight your "random" poll result subtotals to get the demographics "right."  And therein lies a problem. How do you know that folks within a demographic group break the same between those with land lines and those without? Or folks who respond to polls and those who hang up the phone? Or just how much of the subgroup will show up to vote, particularly the cell phone folks, but also when stated intention to vote does not match previous behavior for a subgroup. It is a particularly serious problem with Hispanics. They must be rather massively under-polled, and need a large re-weight.

I note Blumenthal says they just re-weight to census data. OK, whatever. That seems rather crude to me. The same issue obtains. There is no escape.

So if after you create your demographic turnout model (based on the past presumably), and you get a sample that is has say a Dem margin of 13%, maybe you should start to worry. So it is not quite as simple as stating that those who re-weight based on partisan affiliation, are just hopeless, clueless, innumerate knuckle draggers who slept through their statistics course, or never bothered to take one. It all depends. And to add to the stress, the demographics have become more volatile from 2004 to 2006 to 2008 to 2010, bouncing, bouncing all around a bit - particularly as the young and the black found their pied piper, and their turnout went up, up and away.

And the truth is that every election is so unique, and the data points so few anyway, that this demographic re-weighting stuff just has to be more art than science.

Oh, to answer the poll:  I don't know!

[Torie]

Yes, that is the claim, but as I said, just re-weighting based on census data is not a magic wand of accuracy.  Moreover, that still leaves the problem of assuming that those who have land lines, and answer the phone, will have the same voting habits as those who do not within their subgroup. And suppose that 85% if Hispanics say they are likely to vote, to take an extreme example. Does one just throw historical voting propensity habits into the dust bin?  So many conundrums, so little time.

In short, there is no true random sample of those who will be actually voting. It is impossible to obtain such a sample. So you have to try to replicate it, in a zero gravity environment laboratory as it were, and there is no such laboratory so pristine and pure.

[Torie]

The issues with landlines and cell phones is something that polling companies are dealing with. However, it is not something new and certainly would not explain the shift in polling in the last month.

Yes, the trend thing is harder to blow off as  a posited ephemeral zephyr against the prevailing wind direction, unless the internal methodology changed. That is why I always find more interesting intra-polling firm trends, than I do inter-polling ones.

[Torie]

Yes, that is the claim, but as I said, just re-weighting based on census data is not a magic wand of accuracy.  Moreover, that still leaves the problem of assuming that those who have land lines, and answer the phone, will have the same voting habits as those who do not within their subgroup. And suppose that 85% if Hispanics say they are likely to vote, to take an extreme example. Does one just throw historical voting propensity habits into the dust bin?  So many conundrums, so little time.

In short, there is no true random sample of those who will be actually voting. It is impossible to obtain such a sample. So you have to try to replicate it, in a zero gravity environment laboratory as it were, and there is no such laboratory so pristine and pure.

The concerns you raise here are valid ones, obviously. But your previous post had conveyed the misleading sense that Mark Blumenthal had said that reputable polling firms used some kind of model to project what share of the electorate would belong to different demographic groups. I just wanted to make sure we were all clear that reputable polling firms don't do that, and that Mark Blumenthal wasn't being cited as an authority claiming that they do.
There are obviously enough difficulties with polling data as it is without introducing new ones.

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I put my comment in bold just to do my part in making sure your little point is not lost. I am not sure I quite believe Blumey that all the pollsters other than bad boy Rass actually are census junkies however. I suspect some have their own spices in the cupboard. But that is his claim.

[Torie]

All other evidence aside, one would think that the pollsters will get better at their craft as time goes on, not worse.

Blame cell phones and more persons of color - particularly Hispanics.