http://www.newyorker.com/news/benjamin-wallace-wells/sanders-trump-and-the-rise-of-the-non-voters

Two important things from this article:

1)  Trump and Sanders are drawing in non-voters (which as I mentioned in another post will make it interesting to see what happens if they aren't running in the general election)

2)  Except for questions around racism, xenophobia and nationalism, answers from many of Trump and Sanders supporters were cery similar in regards to economic policy.  This is why some if only one is running in the general election he might get voters who supported the other person in the primary.