Based on a "phone poll" telephone call I received, I'm inclined to think that the reason polls seem to favor Demunists has to do with polling techniques, and the fact that they often over sample Demunists.
I got polled over the phone the other day on the subject of "Stem Cell Research". The question of whether or not I would support the government's subsidy of corporations for such research, and whether it involved use of aborted human embryos or fetuses or not, was not mentioned. The poll was worded in an almost comically biased fashion:
"Considering the fact that Stem Cell Research...." (no mention of government subsidy or not, and not specifically asking about aborted human embryonic or fetal research, just "stem cell")
"....will lead to the cures of diseases like Parkinson's Disease, Alzheimer's Disease, and others...." (Oh really? What definite breakthrough, with specifically aborted embryonic or fetal human material, has happened? At this point the researchers are taking shots in the dark and hoping for the best; nothing definitive has happened)
"....and will not lead to human cloning...."(Oh really? What laws stop them?)
"....or more abortions...."(Oh really? Why WOULDN'T there be a greater incentive for abortions now that there is a commodity to be harvested for profit?),
"....and will actually be the greatest thing since sliced bread, and only a cold hearted fiend would be against it, if the election were held today, would you be more or less in favor of a candidate who supported it?"
OK, I am exaggerating the bias in the poll's wording a little, but just a little.
And I took great relish in answering, in as contemptful a voice as I could muster, "LESS....in fact, I favor tying Michael J. Fox to railroad tracks and twirling my handlebar Snidely Whiplash moustache with the train coming to run him over as he makes jerky motions and cries for help. Muahahahahaha...."