SAN FRANCISCO (AP) -- History already in hand, Hillary Clinton will celebrate becoming the first woman to lead a major American political party Tuesday following votes in California, New Jersey and four other states.

Clinton reached the 2,383 delegates needed to become the presumptive Democratic presidential nominee on the eve of Tuesday's voting, according to an Associated Press tally. Her total is comprised of pledged delegates won in primaries and caucuses, as well as superdelegates - the party officials and officeholders who can back a candidate of their choosing.

Clinton greeted news of her achievement with a measured response, wary of depressing turnout and eager to save the revelry for a big victory party Tuesday night in Brooklyn. During a campaign stop in California, Clinton told a cheering crowd she was on the brink of a "historic, unprecedented moment," but said there was still work to do in her unexpectedly heated primary battle with Vermont Sen. Bernie Sanders.

"We're going to fight hard for every single vote," Clinton declared.

Heading into Tuesday's voting, Clinton has 1,812 pledged delegates and the support of 571 of the 714 superdelegates, according to the AP count.

The AP surveyed the superdelegates repeatedly in the past seven months. While they can change their minds, those counted in Clinton's tally have unequivocally told the AP they will support her at the party's summer convention.

During a rally Monday evening in San Francisco, Sanders said a victory in California would give him "enormous momentum" in his bid to push the Democratic primary to a convention fight. Sanders is urging superdelegates to drop their support for Clinton before the gathering in Philadelphia, arguing he is a stronger candidate to take on presumptive Republican nominee Donald Trump.

But Sanders has so far been unable to sway the superdelegates, and there were signs Monday that he was taking stock of his standing in the race. Speaking to reporters, Sanders said he planned to return to Vermont on Wednesday and "assess where we are" following the California results.