Six states hold Democratic presidential contests on Tuesday: California, Montana, New Jersey, New Mexico, North Dakota and South Dakota. Ahead of the key primary in California, the number of registered voters has surged to a record high. Of the nearly 650,000 people who registered in the final six weeks, more than three-quarters were registered Democrats. Campaigning in Fairfield, California, Vermont Senator Bernie Sanders said he will win the state if voter turnout is high.

Sen. Bernie Sanders: “And I will tell you—you don’t have to turn on the TV on election night, because I will tell you exactly what will happen—what will happen is, if you hear that there is a large voter turnout, we will win. If you hear that there is a very large voter turnout, we’ll win by a lot. If you hear that there is a low voter turnout, we’ll lose. Just the facts.”

Hillary Clinton touted her ties to California during a campaign stop in Oakland.

Hillary Clinton: “My first legal job was the Children’s Defense Fund, but I also worked for a law firm right here in Oakland. I worked here in Oakland in the summer of 1971. And I had just started dating my husband. This may be too much information. It was the spring of 1971.”

Hillary Clinton is close to the threshold of 2,383 delegates needed to win the nomination, and could declare victory on Tuesday. But a large portion of her lead comes from unpledged superdelegates who could change their vote at any time. Heading into Tuesday’s primaries, Clinton has 290 more pledged delegates than Sanders, but leads him 548 to 46 among unpledged superdelegates. Sanders has vowed to remain in the race, saying the Democratic convention in July will be a contested convention.