President Barack Obama sees himself as the “lifeguard” of the Democratic party and will step in to head off a major disaster, like the party nominating an open socialist, according to an extensive report published Tuesday in Politico.

The Daily Wire already reported that Obama has been discussing the slate of potential 2020 Democratic presidential nominees with friends, and that he may have even tried to kneecap his former vice president, Joe Biden, telling advisors that he doesn’t believe Biden has the wherewithal to serve in the nation’s highest office.

But HuffPo caught a second tidbit from journalist Ryan Lizza’s extensive expose on the former president’s mostly covert involvement in the 2020 selection process: Obama will step in and even “raise his voice” if necessary to keep the party from nominating Sen. Bernie Sanders (I-VT).

“Back when Sanders seemed like more of a threat than he does now, Obama said privately that if Bernie were running away with the nomination, Obama would speak up to stop him,” Politico reports.

Sources close to Obama confirmed for Lizza that the former president, who campaigned on a far left platform but governed further towards the middle (though, still, substantially left of center), doesn’t view Sanders as a Democrat, and that, were Sanders to come close to snagging the all-important Democratic nod, Obama, who views himself as a “guardrail” and conscience for the party, would use his influence to reroute the nomination.

“He hasn’t said that directly to me,” an unidentified advisor told Lizza. “The only reason I’m hesitating at all is because, yeah, if Bernie were running away with it, I think maybe we would all have to say something. But I don’t think that’s likely. It’s not happening.”

“Bernie’s not a Democrat,” another source added, matter-of-factly.

All Obama has said publicly is that he plans to support the nominee, though he also said that in 2016, and his lack of enthusiasm for then-candidate Hillary Clinton probably had an impact on her reception among Democratic voters overall. Obama’s involvement in Clinton’s campaign was limited, it seems, by design, and he stepped in, then, only to privately suggest to Bernie Sanders that he should forget his open challenge for the nomination and throw his — and, subsequently, his supporters’ — support behind Clinton as the nominee.

But there have been hints that Obama is steering the Democratic party away from nominating or even, for that matter, tolerating Democratic socialists within its ranks. At a meeting of top Democratic fundraisers in early November, Obama cautioned the party from moving too far left — a shift he seems to believe will cost them the 2020 election.

“Even as we push the envelope and we are bold in our vision, we also have to be rooted in reality,” Obama said, according to The Hill. “The average American doesn’t think we have to completely tear down the system and remake it.”

That was widely seen as a swipe against Sanders, but also against fellow progressive Sen. Elizabeth Warren (D-MA) who, just before Obama’s meeting with donors, had unveiled her “plan” to fund a vast and expensive public health care system. Although Obama aligns better with Warren than Sanders, some experts suggested at the time that Obama views the Affordable Care Act, or “Obamacare,” as a signature achievement of his presidency and takes Warren’s push for a more comprehensive health care overhaul personally.

Obama earned ire from progressives for his words, and he’ll likely earn similar ire for the news that he does not plan to back Sanders in any challenge,

Fortunately for Obama, it’s not likely he’ll have to step in to head off either Sanders or Warren. The pair are running behind nationally, with Sanders leading in only a single poll in New Hampshire and running at least third nationwide, and Warren now slipping an average of ten points in all early primary states.