"Let him make that decision. Give him time," Vice President Joe Biden said Wednesday when asked if it was time for Sanders to halt his effort.
Sanders vowed to continue to his campaign to the last contest in the District of Columbia next Tuesday. But about half his campaign staff is being laid off, two people familiar with the plans said Wednesday. They spoke on condition of anonymity because they weren't authorized to speak publicly about the layoffs.
Clinton cruised to easy victories in four of the six state contests Tuesday. With each win she further solidified Sen. Sanders' defeat and dashed his already slim chances of using the last night of state contests to save his flagging bid.
The victories allowed Clinton to celebrate her long-sought "milestone" - the first woman poised to lead a major political party's presidential ticket. Standing before a flag-waving crowd in Brooklyn, the former secretary of state soaked up the cheers and beamed.
"Barriers can come down. Justice and equality can win," she said. "This campaign is about making sure there are no ceilings, no limits on any of us. This is our moment to come together."
Clinton had already secured the delegates needed for the nomination before Tuesday's contests, according to an Associated Press tally. Still, Sanders had hoped to use a victory in California to persuade party insiders to switch their allegiances. Sanders picked up wins in Montana and North Dakota, but Clinton won substantially in California.
Clinton's victory in California assured her a majority of pledged delegates - those chosen in primaries and caucuses. That's notable because Sanders has argued that his White House bid remained viable as long as he stood a chance of winning a majority of those delegates. He would have needed a landslide Tuesday to reach that goal.
Donald Trump turns attention toward defeating Hillary Clinton
Sanders is under intense pressure from top Democrats hoping to coax him gently out of the race, win over his voters and turn to the task of challenging Trump, the presumptive GOP nominee. Sanders planned to meet separately Thursday with President Barack Obama and Senate Minority Leader Harry Reid.
While Reid has stopped short of publicly calling for Sanders to drop out, other senators were less restrained Wednesday. Sen. Bill Nelson of Florida said Sanders should "stand down" and Sen. Jeanne Shaheen of New Hampshire said would like to see him wind down his candidacy sooner rather than later.
The president is expected to endorse Clinton in the coming days. He called both Clinton and Sanders after voting wrapped up late Tuesday.
There were signs Sanders was listening to Democrats. In his typically passionate remarks, the socialist firebrand repeatedly noted late Tuesday night that "we are in this together" and argued that a tenet of his campaign was that "we will not allow right-wing Republicans to control our government."
As the Democratic race was wrapping up, Republicans were unraveling anew. Despite handily winning GOP contests in California, New Jersey, New Mexico, South Dakota and Montana, Trump was in damage control mode over his ethnicity-based attacks on a Hispanic judge that had party leaders in fits. After one senator rescinded his endorsement and House Speaker Paul Ryan called the comments "racist," Trump sought to calm worries with a rare, scripted victory speech for his new batch of primary wins..
"I understand the responsibility of carrying the mantle and I will never, ever let you down - too much work, too many people, blood, sweat and tears," Trump said, reading from a teleprompter at a rally at one of his golf courses in suburban New York City. "I will make you proud of your party and our movement, and that's what it is, is a movement."
Despite Ryan's concerns about Trump's remarks, the speaker reaffirmed his support in a closed-door meeting with fellow GOP lawmakers Wednesday. It was Ryan's first meeting with House Republicans since endorsing Trump last week after initially withholding his support.
A Ryan aide said the speaker told his colleagues he would continue criticizing the billionaire when needed. Ryan's remarks were greeted by applause, according to the aide, who spoke on condition of anonymity to describe the private remarks.
Clinton now has 2,184 pledged delegates - or more than half of the 4,051 total. Sanders has 1,804.
When including superdelegates, or party officials who can back any candidate, Clinton's lead is much bigger - 2,755 to Sanders' 1,852.
It takes 2,383 to win. Clinton crossed that threshold Monday, according to the AP tally
Sanders and some in his army of die-hard supporters expressed frustration about the survey. As he addressed supporters in Los Angeles, the crowd chanted "Media is corrupt."
Both Clinton and Trump made overtures toward an energized and passionate pool of voters. Trump noted he and Sanders both oppose the president's Pacific Rim trade deal, and he sympathized with frustration for having "been left out in the cold by a rigged system of super delegates."
Clinton thanked the senator for driving the debate over economic mobility and income inequality and tried to show she absorbed some of his message. Mostly, she expressed empathy of a candidate who knows the bitter taste of defeat.
Still, it was her night to celebrate.
Her campaign produced a video to introduce her speech, chronicling women's rise in politics from the suffragettes through Clinton's own concession to speech to then-Sen. Obama, eight years ago. Then, she had thanked supporters for helping her put "18 million cracks" in the "highest, hardest glass ceiling."