President Obama spoke with Bernie Sanders on Sunday to discuss the lingering Democratic presidential primary, less than 48 hours before California voters head to the polls.

The two chatted by telephone for about 45 minutes, with Sanders taking the call while he was on a highway between events in the Los Angeles area, according to a person familiar with the conversation who was granted anonymity to discuss it. 

Though the two have spoken from time to time in recent months, the timing of their latest call is another sign that leading Democrats are ready to wrap up the primary and form a united front against Donald Trump in the general election. Obama could endorse Clinton as early as Wednesday, White House aides say, but he has long signaled that he would take care to respect Sanders' decision-making. 

Sanders, down in delegates and the path narrowing in his quest for the Democratic presidential nomination against front-runner Hillary Clinton, has insisted that he will remain in the primary until the party’s nominating convention in Philadelphia in July.

As he has traversed California in recent days, Sanders has insisted that Clinton will not have enough delegates to become the party’s nominee.

Hillary Clinton kicked off her star-studded final sprint through California at a boisterous rally at Plaza Mexico in Lynwood on Monday, urging voters to head to the polls.

"Tomorrow is a really big day," she told several hundred supporters, one of whom yelled that it was “Hillary Day!” "Let’s hope it is," she responded. "I would be deeply honored and humbled for it to be Hillary Day. But that depends on all of you and your family and your friends and your colleagues."

Clinton is widely expected to clinch the Democratic nomination before the polls close in California on Tuesday. But the contest between Clinton and Democratic rival Bernie Sanders has tightened in California, and the candidate and her campaign have been working hard to avoid an embarrassing loss.

Kicking off his last day of stumping in California, Bernie Sanders was eager Monday to exhort voters to participate in Tuesday's pivotal primary. He was not so keen to talk about what comes afterward.

Sanders pinned his chances in the state's primary to voter turnount.

"If the turnout is high tomorrow, we will win," he said. "If the turnout is very high, I think we will win by big numbers. If turnout is low, we will probably lose." 

Hillary Clinton will very likely declare before the votes are even counted in California on Tuesday that she has clinched the Democratic nomination, as her big lead in New Jersey could earn her the final delegates she needs earlier in the evening.

Speaking to reporters in Compton on Monday, Clinton started to lay the groundwork for claiming victory, while being careful not to discourage California supporters from voting.

“It’s not over until it’s over, and tomorrow is a really important day, particularly right here in California,” she said.

Fallout from Donald Trump's latest inflammatory comments -- these directed at a Latino judge overseeing a fraud lawsuit against the now-defunct Trump University -- continued on Monday with a host of Republicans condemning the billionaire businessman.

Florida Sen. Marco Rubio, who battled Trump through much of the GOP primary before exiting the race in March after Trump defeated him in his home state, dismissed the comments as ignorant.

“It’s wrong and I hope he stops,” said Rubio in an interview with a local Florida television station.

On Sunday, Trump, the presumptive Republican nominee, said on CBS the ethnicity of U.S. District Judge Gonzalo Curiel, who is presiding over the suit, should disqualify him from the case. In the interview, Trump said Curiel is “a member of a club or society very strongly pro-Mexican,” and is unable to be unbiased in the court hearing. Trump also falsely referred to the Indiana-born judge as "Mexican."

Trump announced his candidacy last year by describing Mexican immigrants as mostly “rapists” and drug runners. Moreover, Trump has repeatedly vowed to build a massive wall along the U.S.-Mexico border, comments that have sparked outrage among immigrant-rights groups.

“I don’t think it reflects well on the Republican Party. I don’t think it reflects well on us as a nation,” added Rubio, who has said he will support the GOP nominee.

Former Gov. Arnold Schwarzenegger has studiously avoided weighing in on presumptive GOP presidential nominee Donald Trump.

But on Monday, he let his ballot do the talking.

Schwarzenegger, a Republican, voted for Ohio Gov. John Kasich on his mail-in ballot, said spokesman Daniel Ketchell. 

Hillary Clinton’s brother-in-law Roger was arrested on suspicion of driving under the influence in Redondo Beach on Sunday night, police said.

Roger Cassidy Clinton was arrested about 8:05 p.m. and and is being held in the city jail on $15,000 bail, jail records show. If he does not post bail, he’ll likely be arraigned Monday afternoon in a courthouse in Torrance, said Redondo Beach police Lt. Joe Hoffman.

About 7:20 p.m., a motorist called police to report a driver southbound on Pacific Coast Highway, possibly drunk and driving in “an erratic manner,” police said in a statement.

Democrats in Indiana condemned Donald Trump on Monday for his assertion that the judge trying the Trump University lawsuit cannot do so fairly because of his Mexican heritage.

The judge, Gonzalo Curiel, is an Indiana native. Trump accused him of being unfit to serve as presiding judge in the case, saying that his Mexican heritage presents "an inherent conflict of interest."

But Indiana Democrats aren't buying it.

In the neck-and-neck battle in Tuesday’s California primary, Hillary Clinton's campaign is confidently predicting victory.

"Like a lot of states, it’s close, it’s competitive. I think we win a tight race," top Clinton strategist Joel Benenson said Monday on CNN’s “New Day.”

Even if Clinton wins, rival Bernie Sanders has vowed repeatedly to continue to campaign. But Benenson said the Democrats need to come together in the face of the danger that the Republican pick Donald Trump brings.