Democratic Exit Poll:
In November, Donald Trump would be the choice of 44 percent of West Virginia Democratic primary voters who supported Bernie Sanders Tuesday, CBS News early exit polling found.
But support for Trump in the general election is largely driven by independents who were allowed to vote in West Virginia's Democratic primary. More than half would back Trump against either Hillary Clinton or Sanders.
Thirty-six percent of the Democratic primary voters are independents, compared to just 18 percent in 2008.
Campaigning in San Francisco Tuesday, Sanders told reporters he's optimistic not only about his prospects in West Virginia, but in the other remaining states voting by June 7.