An Associated Press count of pledged delegates won in primaries and caucuses and a survey of party insiders known as superdelegates shows Clinton with the overall support of the required 2,383 delegates. Now the presumptive nominee, she will formally accept her party's nomination in July at the Democratic National Convention in Philadelphia.
But neither she nor rival Bernie Sanders seemed much interested in acknowledging it.
Clinton briefly referred to the AP count Monday at a rally in Long Beach but downplayed its significance ahead of Tuesday's spate of primaries, including California's.
“According to the news, we are on the brink of a historic, historic, unprecedented moment. But we still have work to do, don’t we?” Clinton told several hundred cheering supporters in a college gym in Long Beach. “We have six elections tomorrow and we’re going to fight hard for every single vote, especially right here in California.”
And at Sanders' rally in San Francisco on Monday night, it was as though the call was never made.
Sanders did not once cite the AP's report during a 45-minute speech. Instead, he stuck with familiar themes such as income inequality, swiped at Donald Trump for his "bigotry" and contrasted himself with Clinton on issues including the minimum wage, fracking and the use of super PACs.
Above all, he insisted that Tuesday's primary in California would be pivotal.
“Tomorrow, as you all know, there is a very important primary here in this beautiful state," Sanders said, standing in San Francisco's Crissy Field with the Golden Gate Bridge cloaked in fog in the background. "This is the most important primary that we have had in the entire Democratic nominating process."