Those polls, on average, missed an easy Clinton rout in California — and they seem to have missed her resilience with Latino voters. Clinton won all 12 of the California congressional districts where Latino voters make up supermajorities of the population. (Sanders appears to have won just two districts, the largely white and rural 1st and 2nd districts of Northern California.) Both Clinton and Sanders campaigned in the state's most heavily Latino seat, the 40th, which covers east Los Angeles. There, 86.6 percent of the population is Latino, and 55.4 percent of voters broke for Clinton.
It was a similar story across the state, although Sanders's vote was stronger where voters skewed younger. Clinton did worst — just 51.5 percent of the vote — in the 34th Congressional District, which is 66.5 percent Latino and covers downtown Los Angeles. She did only slightly better (52.0 percent) in Orange County's 46th Congressional District, one of the parts of the state that swung from Republican to safely Democratic as younger Latinos moved in.
The rest of the picture is below. In all of these districts, save CA-29, Clinton ran ahead of her statewide margin.
CA-16 (Central Valley): 58.1 percent Latino, 58.7 percent for Clinton.
CA-21 (Central Valley): 72.1 percent Latino, 62.7 percent for Clinton.
CA-29 (San Fernando Valley): 67.7 percent Latino, 53.7 percent for Clinton.
CA-32 (East LA sprawl): 61.9 percent Latino, 58 percent for Clinton.
CA-35 (Inland Empire): 70.0 percent Latino, 56.6 percent for Clinton.
CA-38 (East LA suburbs): 61.2 percent Latino, 56.9 percent for Clinton.
CA-41 (Riverside County): 59.1 percent Latino, 56.4 percent for Clinton
CA-44 (LA County): 70.5 percent Latino, 60.1 percent for Clinton.
CA-51 (San Diego and Imperial County): 69.1 percent Latino, 58.0 percent for Clinton.
With thousands of ballots still to be counted, it's likely that the overall turnout for the primary will fall short of 2008. (That year, and only that year, California moved its contest to February.) That leaves a mystery about the votes of the more than 1.8 million Californians who registered this year, something that the Sanders campaign expected to help it cut into Clinton's margin, or even surpass her.
But a lot of the new registration stemmed from an effort to get Latino voters on the rolls, supercharged by the reaction to Donald Trump. In the closing week of the campaign, Sanders and Clinton had overlapping anti-Trump messages. Sanders would light up his audiences by promising that "Donald Trump will not be elected president," so long as Democrats gave him the nomination. Clinton, who switched up her campaign schedule when Sanders seemed to be gaining in California polls, arrived in the state last week with a headline-conquering speech against Trump. It's hard to say what voters listened to. It's easy to see that Sanders did not win his hoped-for breakthrough with Latino voters.