PPP poll on Walker 'do-over' also oversamples to the left

If Wisconsin voters could get a do-over, they would reject Gov. Scott Walker and instead elect his Democratic opponent — at least, that’s what Public Policy Polling is claiming to be the case in their latest poll.

But William Jacobson takes a look at the numbers, and finds that PPP oversampled Walker’s opposition by about 6 points. And like the NYT/CBS poll I dissected earlier (which also oversamples Democrats), the PPP oversamples union households.

I guess I just have to chuckle. Two major polls hit like a one-two punch, and it just happens to be that both appear to make the same sample errors.