Looks like a very poor poll - I think the "Junk" Label could be added - There are no break-ups of number or % of voters under age 18-29, over 65 etc which could decide. No breakup of whites, blacks, hispanics in the Dem Primary.
It's a random sample - 748 Landline & 655 Cell for both parties - No breakups of one. The landline number seems such that it is likely to have a more older mix than other polls thus favoring Clinton.
Regardless of results, looks a poor man's poll.
One notable thing - 30% of Sanders supporters would consider voting 3rd party vs 6% of Clinton's!
A good portion of Sanders'supporters are not Democrats and wouldn't have voted for her or any Democrat not named Bernie Sanders. Yet both beat Trump by similar margins.