Those circulating the "Sanders is doing better than Obama at this point" meme should keep in mind...

[MFrohike]

52. Actually, no

The issue of shrinking population is a big issue. Don't take my word for it. Nate Silver surveyed the major pollsters last year during the election and they found it to be quite important regarding accuracy. The issue isn't land lines vs cell phones, but of total respondents. That's the population issue.

The parallel to Literary Digest is the inaccuracy due to an unrepresentative population. The issue for Literary Digest was the method of selection, not the method of contact (which was a mailed sample ballot, not a phone call). In this case, the population is becoming unrepresentative via self-selection, not necessarily due to errors by the polling company. It's not that the same mistakes are being made, it's that the same problem of inaccuracy is arising due to the same fundamental problem of population. The difference is how the population is selected, not the result.