Hillary Clinton won four out of five states on Tuesday night. Now she has 90 percent of the delegates she needs to win the Democratic nomination.
Hundreds of staffers working for the Bernie Sanders campaign were let go on Wednesday, but the campaign insisted layoffs don't mean he's giving up.
"I am very good at arithmetic, and I can count delegates. We are behind today. But you know what? Unusual things happen in politics," Sanders said.
Campaign aides say they will focus most of their remaining resources on winning California on June 7th. The strategy complicates Clinton's efforts to win over his supporters.
"I applaud Senator Sanders and his millions of supporters for challenging us to get unaccountable money out of our politics," Clinton said in her victory speech on Tuesday night.
Sanders rejected the notion that he's helping Republicans by continuing to criticize his party's likely nominee.
"They don't need my speeches to talk about Hillary Clinton. They will go after Hillary Clinton, by the way, in ways I have never ever gone after Hillary Clinton," he said.
But his decision to stay in the race till the end worries some democratic voters, like William George of Philadelphia.
"If you don't support her there's a good chance that Trump could very well win," George said.
The Sanders campaign insists he is invigorating the party and say if he's the nominee, they'll hire all those laid off workers back for the general. But at this point he'd need to win 80 percent of the remaining delegates to catch up.