With a week remaining before the California Democratic primary, Hillary Clinton picked up a pair of high-profile endorsements - including one from the state's iconic governor - while Bernie Sanders insisted that it's still too soon to close ranks around the party's likely nominee.
California Governor Jerry Brown, argued in an "open letter" to his state's Democrats that Clinton represents the best chance to defeat the "dangerous" candidacy of Republican Donald Trump, saying that "this is no time for Democrats to keep fighting each other".
A major national environmental group, the NRDC Action Fund, also cited Trump in its decision to back Clinton, suggesting that it was time for liberal groups to rally around her. Trump's policies would "take us back 100 years," the group said.
Sanders, who is maintaining an aggressive campaign schedule in California, meanwhile argued that he still has a shot to prevail and warned supporters that the media could skew election results by prematurely declaring Clinton the presumptive nominee next week.
He was referring to speculation that the media will give Clinton that designation on Wednesday after the polls close in New Jersey, which should help deliver the remaining delegates she needs to clinch the nomination if superdelegates are factored in.
That will be hours before Californians finish voting. Sanders has long argued that the votes of superdelegates - party officials and other Democratic elites - should not be counted until the party's convention, when their preferences become official.
At a rally in Santa Cruz, California, Sanders warned that the media is expected to declare "the primary process is over, Secretary Clinton has won". His statement was met with boos.
"That is factually incorrect. It's just not factually correct," the senator from Vermont said, predicting that he would win California and some other states on Wednesday and head into the convention with enough momentum to flip allegiances of superdelegates who previously announced support for Clinton.
Though Clinton's campaign remains confident about her prospects for securing the nomination, it has taken several steps to avoid an embarrassing loss in California, including cancelling an event in New Jersey on Friday in order to head to the West Coast sooner.
During an interview today with MSNBC, Clinton did not give any hint of nerves over the outcome of California's primary, however.
"I'm feeling very positive about my campaign in California," she said. "We are working really hard."
Brown waited until a week before his state's primary to issue what many perceived as a less-than-enthusiastic endorsement of Clinton.
"I have decided to cast my vote for Hillary Clinton because I believe this is the only path forward to win the presidency and stop the dangerous candidacy of Donald Trump," Brown wrote. He spelled out his reasons, including Trump's opposition to global agreements on climate change, but did not urge Democrats to follow his lead.
"The general election has already begun," Brown wrote. "Hillary Clinton, with her long experience, especially as Secretary of State, has a firm grasp of the issues and will be prepared to lead our country on Day One."
Clinton's campaign emailed a copy of the letter to reporters without comment.
Brown's support follows decades of occasionally acidic criticism of both Hillary Clinton and former President Bill Clinton. One of the longest-running feuds in Democratic politics began when Brown ran against Bill Clinton in the Democratic presidential primaries in 1992 and won five states.
Sanders told a local TV reporter that he was not surprised that Clinton picked up another endorsement from a governor, given "the Democratic establishment [is] supporting Hillary Clinton".
"I like Governor Brown," Sanders told KCBS-TV. "But people can make their own choices."
In its statement, the NRDC Action Fund, a political affiliate of the Natural Resources Defence Council, praised Clinton but said its first endorsement of a presidential candidate reflects a need for left-leaning groups to unite against Trump.
Rhea Suh, president of the NRDC Action Fund, specifically cited Trump's recent energy speech in North Dakota as one of the main rationales for the announcement.
"Donald Trump . . . has recently outlined a disastrous and frankly nonsensical environmental agenda - suggesting that he would tear up the Paris climate agreement, and that there is no drought in California," Suh said. "His plan for his first 100 days would take us back 100 years, and America cannot afford to indulge his climate conspiracy theories."
Sanders and some of his most loyal supporters sought to advance the argument that media organisations should hold off on declaring Clinton the party's presumptive nominee next week. "Neither candidate will have received the number of pledged delegates that he or she needs to become the Democratic nominee," Sanders said at a rally in Santa Cruz.
"Here's what's really bad," said RoseAnn DeMoro, the executive director of the pro-Sanders union National Nurses United, after the candidate held an event in Emeryville, California, with its members. "At 5 o'clock, evidently, there's this plan for the media, if Clinton wins New Jersey, to say: 'This is over. She's got it locked up.' That's a lie. That's a lie."
"It's a lie," a nurse in the audience said loudly.
DeMoro was referring to not-so-secret plans for media outlets, which have been keeping their own delegate counts, to mark the moment when Clinton wins the 2383 delegates needed to clinch the nomination.
AP's count, the basis for many other media outlets, has Clinton at 2312 - 1769 won in primaries and 543 superdelegates. There are 12 delegates up for grabs in the US Virgin Islands on June 5, and 67 more in Puerto Rico the next day. At her current pace, Clinton would hit the 2383 target on June 8 when polls close in New Jersey and the state's 142 delegates are parcelled out. The polls will close in California three hours later.
"So, the idea is that people in California - working people who are getting off work - would think it's over," DeMoro said. "And it wouldn't be over. Not only would it discourage Bernie voters, but all of the other progressive candidates down ballot would be disadvantaged, because voters would think it's over."