Former President Barack Obama was one of the central figures behind Sen. Bernie Sanders’ (I-VT) exit from the presidential race, according to a report from the New York Times.

While Obama failed to publicly support his former running mate throughout the primary race, he quietly worked behind the scenes to encourage the Vermont senator to exit the primary race, having several phone conversations with him over the last few weeks, according to the Times.

The former president reportedly made the first call to Sanders at the end of March, as the coronavirus pandemic worsened and Sanders’ campaign continued to falter, reportedly citing the need to “accelerate the endgame.”

According to the Times, Obama informed Sanders that he had, largely, accomplished his political goal in moving the party further to the left:

In late March, Mr. Obama reached out to Mr. Sanders. The two men would talk at least three more times, with the former president reassuring Mr. Sanders that he had already accomplished much of what he had set out to do, moving the party — and Mr. Biden — substantially to the left, according to two people with knowledge of their interactions.

That much is certainly true for Biden, who over the course of his campaign has embraced positions once deemed too radical by the party. By the end of the race, Biden had openly called for raising taxes, embracing some form of a Green New Deal, and providing government-run health care for illegal immigrants.

According to the Times‘ sources, Obama “mostly listened to Mr. Sanders, who was in a reflective mood, speaking candidly about his post-campaign plans and feelings about the race, the kind of conversation the two men had never had before.”

Nevertheless, it was not until every single one of Biden’s Democrat challengers dropped out of the presidential race that Obama publicly stated, “I believe Joe has all the qualities we need in a President right now.”

@BarackObama / Twitter

“Barack — This endorsement means the world to Jill and me,” Biden said on Tuesday after enduring months of Obama’s public silence. “We’re going to build on the progress we made together, and there’s no one I’d rather have standing by my side”:

Barack — This endorsement means the world to Jill and me. We’re going to build on the progress we made together, and there’s no one I’d rather have standing by my side. https://t.co/0mAjPZeYmd — Joe Biden (@JoeBiden) April 14, 2020

Sanders also formally endorsed his former challenger this week.

“Today I am asking all Americans — I’m asking every Democrat, I’m asking every independent, I’m asking a lot of Republican — to come together in this campaign to support your candidacy which I endorse,” Sanders said on Monday, staying true to his vow to support the party’s ultimate nominee.