About that liberal bias in the polls

'But the pushback goes beyond coverage. Now even the polls themselves are being impugned, with suggestions that they are skewed by left-leaning math. Various conservative bloggers and pundits have complained that a slew of polls showing gains by President Obama were guilty of “oversampling Democrats” and “confirmation bias.”' — NYT

I do not get this. If I could control bias in the polls I would skew them Republican, not Democratic. I like the idea of my opponent have a misguided sense of his own strength, I want  him in the bubble, because  being underestimated is my biggest weapon, raises more cash and makes my final victory all the sweeter. Why on earth would I want to look and sound stronger than I am? Like most Republican conspiracy theories, this one runs afoul of basic plausibility. It's not so much that what they're saying is not true, but that their falsehoods are so insultingly flimsy.  As bad as they are on facts, their fictions are still worse.