Has Barack Obama decided to intervene in the 2020 Democratic primary after all? Or is this a warning shot across the bow to those who want to attack Joe Biden through Obama’s legacy? Both The Hill and the New York Times report that the former president’s interest in his VP’s presidential campaign is both more active and deeper than first thought.

The New York Times says it began before Biden officially launched:

Up until earlier this year, he suggested Mr. Biden would be better off sticking with his vague promise, made during the audition for the vice presidency, that his short-lived 2008 presidential campaign would be his last.

That has changed: While initially skeptical of Mr. Biden’s decision to run, Mr. Obama, driven by affection and loyalty, has been more active in advising his campaign than previously known — going so far as to request a briefing from the campaign before his friend officially joined the fray, according to people close to both men.

“It’s an incredible turn of events, when you think about it,” said Mr. Bayh, who retired from the Senate in 2011. “The question then was, ‘Do you happen to fit the moment?’ The question now is, ‘After all these years, can you turn yourself into an independent source of power, as opposed to being just a loyal and faithful wingman?’ Only time will tell.”

The Hill calls this an “active interest,” and more than just casual conversation:

Former President Obama has summoned top aides on former Vice President Joe Biden’s presidential campaign to Washington for a personal briefing as Obama appears to be taking an active interest in Biden’s campaign for the Democratic nomination.

The New York Times reported Friday that the two met last month for lunch and that Obama summoned top members of Biden’s campaign to his Washington, D.C., home earlier this year for a briefing on Biden’s communications and digital media strategies ahead of the former vice president’s campaign launch.

Obama’s interest and quiet advice to Biden’s campaign comes despite the former president’s vow that he will not make an endorsement in the 2020 Democratic Party presidential primary, even as Biden has aligned himself with the former president’s legacy and often cited Obama’s vetting of him in 2008 as a strength on the campaign trail.

As interventions go, Obama’s seems rather mild. The briefing took place months ago, and the last lunch between Obama and Biden took place in July. Obama would probably welcome other candidates to a lunch, and might even offer a little advice to them as well. This isn’t close to an endorsement, or even acting as Biden’s part-time consigliere, although Biden could certainly use the assistance.

What, then, is the purpose of this narrative, driven by sources in both Biden and Obama camps? It seems like a throat-clearing exercise by Obama and his team, especially after the last debate when Biden’s opponents attacked him by shredding Obama’s legacy. At times, Biden’s competitors sounded more interested in running against Obama than Donald Trump, despite the fact that Obama remains incredibly popular in retirement, especially among Democratic voters.

Thus we have “more than two dozen” sources within the Obama and Biden ranks talking about the complex relationship between the two top men in the most recent Democratic administration. It’s not all peaches and cream in this portrait;  the NYT story discusses Obama’s reservations about Biden, and Biden’s frustrations with Obama, and The Hill picks up on both.

However, the leaks and the narrative send an unmistakable message from ObamaLand: Mess with my legacy at your peril. If other Democrats continue to take shots at Obama, the former president might well decide to take an even more active interest in Biden’s campaign, up to and including an endorsement that would all but kill off everyone else’s chances of winning the nomination.

It’s a throat-clearing exercise. Other Democrats need to take the hint and find other avenues of attack on Biden. If they give him enough time, Biden will give them all the material they need without forcing Obama to intervene to protect his own legacy.