Former Secretary of State Hillary Clinton was deemed the presumptive Democratic presidential nominee by the Associated Press Monday night as six states, including California, prepared to hold primary elections on Tuesday. In recent weeks, the California race has been recast to be a tight one between Clinton and U.S. Sen. Bernie Sanders (I-VT) after the former first lady previously had a two-digit lead over the senator.

The AP made the call based on ongoing polling of superdelegates, who do not cast their votes for candidates until the Democratic National Convention in July, and Clinton’s wins over the weekend in Puerto Rico and the U.S. Virgin Islands. The Sanders camp said such proclamations are premature seeing as though superdelegates have yet to cast their votes.

“It is unfortunate that the media, in a rush to judgment, are ignoring the Democratic National Committee’s clear statement that it is wrong to count the votes of superdelegates before they actually vote at the convention this summer,” said Sanders’ spokesman Michael Briggs. “Secretary Clinton does not have and will not have the requisite number of pledged delegates to secure the nomination. She will be dependent on superdelegates who do not vote until July 25 and who can change their minds between now and then. They include more than 400 superdelegates who endorsed Secretary Clinton 10 months before the first caucuses and primaries and long before any other candidate was in the race.”

Clinton, who would be the first woman to win a U.S. presidential nomination, said the news marked a “historic, unprecedented moment” for the nation. 

“This is an important milestone, but there are six states that are voting Tuesday, with millions of people heading to the polls, and Hillary Clinton is working to earn every vote,” Clinton campaign manager Robby Mook said in response to the AP’s announcement. “We look forward to Tuesday night, when Hillary Clinton will clinch not only a win in the popular vote, but also the majority of pledged delegates.”

Just hours after Clinton was declared the presumptive Democratic nominee, House Minority Leader Nancy Pelosi (D-CA,12) announced her endorsement of the former Secretary of State Tuesday morning.

“I’m a voter in California and I have voted for Hillary Clinton for president of the United States and proud to endorse her for that position,” Pelosi told ABC’s “Good Morning America.”

“But I hasten to say that it’s not over ’til it’s over,” she said. “Californians haven’t voted, nor have others in five states. So while the nomination may be there in the numbers in terms of superdelegates, I didn’t endorse yet because I am a superdelegate and I think that the matter should be determined by the voters in the state.”

Pelosi also said it would be “fabulous” if Clinton chose a woman for her vice presidential pick.

Clinton will be in Chicago later this month, June 27, for the 50th annual Rainbow PUSH Coalition convention, where she will be the keynote speaker. Clinton will also make an appearance at the convention’s International Women’s Luncheon.