A day after Bernie Sanders won only one of five northeastern primary contests against rival Hillary Clinton, his campaign will lay off more than two hundred staffers in the effort to concentrate its remaining resources on upcoming contests, particularly the June 7 California primary.

Sanders spokesman Michael Briggs told NBC News that the layoffs are part of a “right-sizing” in light of the dwindling number of remaining primary contests.

“It’s a posture of reality,” Briggs said.

Campaign manager Jeff Weaver emphasized that there will still be more than 300 Sanders campaign workers active in remaining states, and he argued that the departure of the 225 staffers is part of the ebb and flow of a presidential campaign.

At its peak, the Sanders campaign had as many as a thousand employees.

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Sanders trails Clinton in the race for delegates by a nearby insurmountable margin. Clinton has secured 1,620 pledged delegates, while Sanders has 1,289. When unpledged “superdelegates” are included in that count, Clinton must only win 20 percent of the remaining delegates, while Sanders would have to win 80 percent of them.

The Vermont senator has vowed to stay in the race “until the last vote is cast.”

But in a statement Tuesday night, Sanders also appeared to signal a pivot towards trying to influence Clinton’s political platform as nominee. “This campaign is going to the Democratic National Convention in Philadelphia with as many delegates as possible to fight for a progressive party platform that calls for a $15 an hour minimum wage, an end to our disastrous trade policies, a Medicare-for-all health care system, breaking up Wall Street financial institutions, ending fracking in our country, making public colleges and universities tuition free and passing a carbon tax so we can effectively address the planetary crisis of climate change,” he said.

Weaver notified those staffers being let go earlier Wednesday.

The layoffs were first reported by The New York Times.

This article first appeared on NBCNews.com.