The primary election season officially ended for the Democrats with a blowout victory for former secretary of state Hillary Clinton in Washington, but her hopes for a swift endorsement by rival Senator Bernie Sanders did not materialise.
Mrs Clinton won nearly 80 per cent of the popular vote in the US capital, trouncing the senator to cap off what ended up being a relatively dominant primary season.
She is projected to have at least 2,800 delegates and more than 16 million votes. She has about 400 more pledged delegates and four million more votes than her rival.
The margin was far more comfortable than the one Mr Obama had over her in 2008, when they were separated at the end by fewer than 100,000 votes.
Mr Sanders, however, made no announcement of his future plans on Tuesday night. He had a nearly two-hour meeting with Mrs Clinton in the US capital but did not take questions after the meeting.
Both campaigns subsequently said the candidates congratulated each other on their respective primary campaigns and talked about unifying the party against presumptive Republican Party nominee Donald Trump.
Mr Sanders recently pledged to take his fight all the way to the nominating convention next month even after Mrs Clinton had secured a majority of delegates a week ago. Most observers now do not expect him to hang on for that long.
Dr Sarah Fulton of the Department of Political Science at Texas A&M University said: "There is not much upside in Sanders remaining in the race until the convention. For one, it plays to the perception that he is disgruntled or delusional, since he doesn't have the delegates to win the nomination."
Predictions of when Mr Sanders might concede vary from a few days to a few weeks. Some analysts say his concession may take a while as the senator is still trying to negotiate with the party over some of his policy priorities, and also because the shooting in Orlando has deflected attention from his core issues of income inequality and campaign finance.
At a press conference in Washington on Tuesday before the results, Mr Sanders focused his remarks entirely on changes he wanted to see in the party.
He called for the party chair to be replaced, for the party manifesto to include his policies and for the end of superdelegates, who are party insiders who get to back whichever candidate they want regardless of the result of the popular vote.
The concern for the party leadership at this point is how Mr Sanders might affect party unity.
On that score, Professor Glenn Altschuler of Cornell University told The Straits Times that although Mr Sanders does not need to concede immediately, he does need to ultimately show some enthusiasm for Mrs Clinton.
"He is going to drop out of the race. Whether he does it on election night or not is not terribly important," said Prof Altschuler.
"It's important that he does it quickly, and that he enthusiastically urges his supporters to work for her, vote for her as a candidate who represents many of his views."