Two groups of California voters — women and Latinos — have powered the Democratic Party’s ascent here and delivered a near-death knell to the state’s Republican Party. A USC Dornsife/Los Angeles Times poll released last week showed that the prominence of those groups also explains why the two hottest candidates this year aren’t running away with the state. Across the country, in the states contested so far, Bernie Sanders and Donald Trump have forwarded a similar message on the topic of the economy: that trade deals have decimated jobs in this country and that those making less money have been...