It really is debatable as to whether or not polls should setup the sample to have percentages based on party affiliation. Some say it is more accurate and some say it isn't. I guess it really depends on who is doing the polling.
So, what you are saying is that this poll could be heavily weighted toward Dems because they were eager to answer the phone on the weekend. Well, could be true.
The sticking point I'm having is that it shows only 1% undecided. That doesn't seem realistic.