SAN FRANCISCO (AP) – As soon as polls closed in California at 8 p.m. Pacific Time, The Associated Press called Bernie Sanders the winner of the biggest prize on Super Tuesday. The AP called the state’s Democratic presidential primary for the Vermont senator even though no votes from Tuesday had yet been counted.

The news agency did so based on results from AP VoteCast, its wide-ranging survey of the American electorate. That election research captures the views of voters on whom they vote for, and why.

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The VoteCast survey found Sanders with a convincing lead in California, with no path for Mike Bloomberg and Joe Biden to catch up. In part, that’s because VoteCast found Sanders with a big lead in early votes mailed in before Tuesday’s election.

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Many of those ballots were cast before Biden’s commanding win in South Carolina and before Amy Klobuchar and Pete Buttigieg dropped out of the race. That means the trailing candidate would need to make up a lot of ground in the vote cast in person by voters at polling places Tuesday. But VoteCast found that vote, too, also favored Sanders.

AP VoteCast is conducted by NORC at the University of Chicago for The Associated Press and Fox News.

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