GWU polling is heavily biased towards liberals and Battleground uses other polling sources as well depending on what it is they are trying to accomplish.
Isn’t Battleground a pretty respected poll? I won’t bother posting the results if it’s supposed to be junk. I do agree that it’s not the same political environment come post-labor day. People are honing in now and paying attention.
Strangely, in 2008, GWU and IBD were touted as the only two polling companies that were accurate. (Coincidentally, they happened to have better results for McCain than others at the time.)
The point being, we need to focus on the polls themselves, and any methodological problems that a particular poll might have, rather than shifting the attack to the polling company.