Clinton's sweep in California is thanks largely to early voting

SACRAMENTO, June 8 (UPI) -- Polls showed them in a relatively close race. On primary day in California, it was not close at all between Hillary Clinton and Sen. Bernie Sanders.

So what happened that led Clinton, now the presumptive Democratic presidential nominee, to deliver a landslide victory over Sanders in the final state race, and the largest one in the country?

Clinton finished with about 400,000 more votes than Sanders, good for a 13-point win, 56 percent to 43 percent. That spread held remarkably steady through the night Tuesday and into Wednesday as vote counts trickled in.

That means the first ballots to be counted, early voting ballots, went heavily to Clinton.

California has gradually shifted from a vote-at-the-polls state to a vote-by-mail state.

In analyzing election returns, 538.com noted the consistency of Clinton's lead from the moment polls closed until she was declared the winner Wednesday morning means she probably had a Golden State victory in the bag days, or even weeks ago -- an impressive show of organizational muscle on Clinton's part.

Californians are allowed to mail in ballots starting 29 days before an election and many of those who choose to vote so early are party loyalists. Clinton has consistently fared better than Sanders among registered Democrats.

Sanders fought in federal court to extend voter registration in California with the hope of expanding the electorate. A judge ruled against the request, saying voters had ample time to sign up in advance of the election. While it is doubtful he could have made up a 13-point difference with just a few more days, it's clear Sanders could have used some extra time to try to offset Clinton's edge with registered Democrats.

Sanders essentially fought Clinton to a tie among voters who showed up on primary day.

There also remains an unanswered question: Just how many votes are still left to be counted?

CNN and NBC News each report that 100 percent of ballots cast in person at polling places are included in the tally, but estimate about 73 percent of the votes have been counted. That means more than one-in-four votes have yet to be counted.

Mailed ballots have to be postmarked by Monday and 538.com reports it's likely Sanders will close some of his gap with Clinton because mailed-in ballots so close to the election tend to hue younger, and closer to Sanders' base of support.

Sanders won northern California, but those relatively small counties paled in comparison to the voter-rich wins Clinton ran up in every other part of the state.

Clinton swept every county home to a large city by 10 percentage points or more, including Los Angeles County, the state's largest. She won in the Bay Area, in both San Francisco County and Oakland's Alameda County. She won upscale Orange County (Anaheim), and Santa Clara County, home to San Jose and Silicon Valley.

Another way to look at Tuesday's results? Clinton over-performed among Latinos, relative to polling headed into the race. Her win among Latinos topped even those impressive urban vote totals.

In congressional districts home to 40 percent or more Latino voters, Clinton won each by an average of 15 percentage points, more than polls suggested.