"Ah. Well, I don't trust SURVEY USA."
I shared your skepticism of SurveyUSA's methodology when they first became well-known a few years ago. However, as someone who tracks the accuracy of pollsters, I have been pleasantly surprised by their performance. I now consider SurveyUSA to be one of the more reliable pollsters, based on the data.
SurveyUSA's website has an extensive database comparing the accuracy of their polling vs. other pollsters who polled the same races. They provide the average Mean Error and Standard Deviation from the final election outcome vs. each competitor, using eight (8) different methods of calculating the above values. This data set goes back to 1992. If you want to research it yourself, the databases are located here:
http://www.surveyusa.com/electiontrackrecord.html
Again, I'm not at all questioning their OVERALL accuracy, which to me is irrelevant, but their ability to get the tight races.