I can’t vouch for the methodology but I can vouch for their Survey Director Jill Darling.
I emailed Jill E. Darling the Survey Director about a week ago when I noticed the scaling of the breakdowns was giving a visual perspective that Hillary was doing better then trump when comparing different charts. She emailed me back and said this ...and two days later the charts were corrected as she promised...All I can say is she is a lady of her word..
“Hello John,
Your point about the need for consistent scales is very well taken! We are in the process of working on making sure we are presenting those subgroup numbers in a way that makes good visual sense. What you pointed out about inconsistent scales is an artifact of the automated process of pulling in data and creating the graphs, and an oversight on our parts, not anything anyone here is doing to try to influence others. We just care about reporting our results!
Appreciated your thoughtful feedback, and wanted to let you know were already on the case. Should see an improvement in the information presented on that page in the next couple of days.
Regards,
Jill
CORRECTION TO MY POST ABOVE>
IT JILL IS WITH USC Dornsive/LAtimes daily tracker