With 806 delegates up for grabs, both Clinton — with 571 left to win — and Sanders — with 862 left — are eyeing California, which holds the majority of voters.
Tuesday could very well decide the ultimate fate of Bernie Sanders, with the primaries — especially in California — offering big delegate pools that are expected to tip the scales and award Hillary Clinton the nomination.
Sanders' campaigners have been going all out in California, which will allocate 546 delegates, 25 short of those Clinton needs to pass the threshold.
Voters will also decide in Montana (27 delegates), New Jersey (142 delegates), New Mexico (43 delegates), North Dakota (23 delegates) and South Dakota (25 delegates), report the New York Times.
Not including superdelegates, Sanders is 291 delegates behind Clinton, but will be hoping to use his popularity in the upcoming contests to convince superdelegates to change their allegiance. Hundreds had already pledged to vote for Clinton months before his campaign picked up.
Leading up to Tuesday’s vote, 44 percent of California Democrats said they would support Sanders and 43 percent said they would back Clinton, according to a new poll from the Los Angeles Times.