Bernie Sanders won Tuesday's primary in West Virginia partly because of Donald Trump's supporters, NBC News reported.
A third of those who voted in West Virginia's Democratic primary say they plan to back Trump in November, according to NBC News exit polls. Sanders won those voters by a wide margin.
In fact, 39 percent of Sanders voters said they would vote for Trump over Sanders in the fall. For Clinton, nine percent of her voters say they plan to come out for Trump in the general election.
West Virginia has an open primary, meaning independents can vote in the Democratic contest. With the GOP nomination wrapped up, it's possible mischievous Trump supporters sought to damage Clinton, the likely Democratic nominee, by voting for Sanders.