While gender is a quota cell in polling, party identification is not a quota cell, as the percentages are not constant and party identification cannot be pegged to census tract data.
Not to census, but to this http://www.gallup.com/poll/15370/party-affiliation.aspx or this http://www.pewresearch.org/data-trend/political-attitudes/party-identification/ . We really are at parity when you consider that Democrats turn out in fewer numbers. They only have a five-point advantage if they all turned out.