538 has a recent article that this nomination process is going to go a long ways towards how polling is done. Seems Trump support falls dramatically in live polls (live phone call not automated and not online).
http://fivethirtyeight.com/features/...d-trumps-fate/
Some other stuff on what polls mean at this point in the process.
http://fivethirtyeight.com/features/...ing-attention/
http://fivethirtyeight.com/features/...r-what-a-joke/