Not the black vote....Not Muslims....

It's this:

"Of 1.25 million who voted in GOP primary, 7% were Democrats, or about 87,000 votes. Only over 19,000 (the gap was originally reported by CNN as 25,000. The NYT revised it to over 19,000 plus once more votes came in) votes separated BS & HRC."

What does this mean? A lot of Democrats scattered their votes in an effort to muck up the GOP race .....A a solid number of Dems (some of the Reagan Democrat variety) voted in the GOP race for Trump/Kasich.....

Basically, strategic voting was happening.

Some regular Democrats and "Reagan" Democrats--because it was an open primary (meaning that you are allowed to vote for whatever party you want to, no matter what you r registered as)--voted for Kasich to make sure Trump didn't score a win (as per various polling interviews). And some voted for Trump.

Folks were very upfront about their strategy: Vote for Kasich in the primary....Vote for Clinton or Bernie in the general....This basically allowed Bernie to pull off the upset.