It's not so much Democrats answering polls more frequently ~ it's about subgroups like the NEA, the abortion rights fanatics and the homosexuals answering polls every single time!
That's been happening all along. It's the reason why gay marriage polls show it's popular, but when put to a vote it generally loses.
The only way pollsters can deal with this is to get out of the polling business.
Why would they want to do that? I'd be pretty darn sure that they voted heavily for Zero, in significantly larger percentage than the general population.