President Obama has come very close to issuing a public endorsement of Hillary Clinton, seen here with Obama during his own Presidential campaign, in 2008. PHOTOGRAPH BY EMMANUEL DUNAND / AFP / GETTY

A couple of weeks ago, on NBC’s “Meet the Press,” Denis McDonough, the White House chief of staff, appeared to indicate that President Obama wouldn’t be backing anyone in the Democratic primary. The President would vote in the Illinois primary, on March 15th, and campaign for whichever candidate emerged from the process, McDonough said. Now, though, Obama has come very close to issuing a public endorsement of Hillary Clinton.

“Look, I’ve gotten to know Hillary Clinton really well, and she is a good, smart, tough person who cares deeply about this country,” Obama said in an interview with Politico’s Glenn Thrush, which was conducted last Friday and published on Monday. The President also described Clinton as “really idealistic and progressive,” evidently addressing the perception among some Democrats that she is too moderate, and noted that Clinton’s experience and her mastery of policy issues would be a big help to her in the Oval Office. “It means that she can govern, and she can start here, [on] day one, more experienced than any non-vice-president has ever been who aspires to this office,” he said.

The President made some favorable comments about Clinton’s rival Bernie Sanders, too, saying that he has “great authenticity, great passion, and is fearless.” But Obama also suggested that crowds were flocking to the Vermont senator because of his novelty, whereas Clinton was being hamstrung by factors beyond her control. “Bernie came in with the luxury of being a complete long shot and just letting loose. I think Hillary came in with the both privilege and burden of being perceived as the front-runner,” Obama said. “You’re always looking at the bright, shiny object that people haven’t seen before. That’s a disadvantage to her.” When Thrush said that some people were comparing Sanders at this stage in the campaign to Obama in 2008, when he beat Clinton, the President pushed back, saying flatly, “No . . . I don’t think that’s true.”

Was Obama just shooting the breeze with a guest in the Oval Office who happened to be carrying a tape recorder? Hardly. It is much more plausible that the President was sending a supportive message to an embattled candidate whom he sees as the best option to replace him, in order to safeguard the electoral position of the Democratic Party and preserve his legacy as a center-left reformer.

For all the differences they had in 2008, some of which lingered, Obama and Clinton both represent the centrist, pragmatic approach to politics that has dominated the Democratic Party since the nineteen-eighties. A victory for Sanders and his insurgent left-wing populism would represent a sharp break with the moderate tradition. In the opinion of many Democrats in the White House and on Capitol Hill, it would also set up the Party for defeat come November, not just in the Presidential race but in congressional elections. And, from Obama’s perspective, it would place a shadow over his biggest achievements, particularly the Affordable Care Act, which Sanders has described as merely a first step in transforming the health-care system.

If the Republicans win the Presidential election and strengthen their grip on Congress, they are likely to repeal large parts of the Affordable Care Act and roll back many of President Obama’s executive orders in other areas, such as environmental regulation. If Sanders were to become President, he would presumably seek to build on Obama’s policies, but there would still be a significant change in approach. In part to try to prevent either of these things from happening, a number of former Obama Administration officials are working for the Clinton campaign. John Podesta, Clinton’s campaign chairman, worked at the White House under Obama. So did Jennifer Palmieri, the Clinton campaign’s director of communications. Joel Benenson, a senior strategist and pollster for the Clinton campaign, carried out a similar role in Obama’s 2008 and 2012 campaigns. The Sanders campaign doesn’t have these sorts of personal ties to the White House.

To be sure, Sanders has been making some complimentary comments about Obama recently. After the President delivered his State of the Union address earlier this month, Sanders wrote that he had “raised some enormously important points . . . regarding the long-term future of our country—much I agreed with.” Step back a bit, though, and it can’t be denied that Sanders built his candidacy, at least in part, on a sense of disillusionment among many progressive Democrats with what Obama has and hasn’t achieved since 2008.

Obviously, the perception among progressives that the Obama Administration failed to hold Wall Street fully accountable for its actions played a big role, but that wasn’t the only thing at issue. Speaking in Wisconsin in 2011, Sanders criticized Obama for continuing “Bush trade policies” and for reportedly mulling over the possibility of imposing cuts to Social Security and Medicare, or raising the retirement age. “F.D.R. and Harry Truman would be rolling over in their graves,” Sanders said. “Fight for a progressive agenda, and do not equivocate. You’re not going to be able to win unless you’re prepared to fight.”

More recently, Sanders has attacked Obama’s political tactics, suggesting that the President had played a Washington insider’s game and failed to mobilize his supporters upon being elected. To win the Presidency, Obama “ran one of the great campaigns in the history of the U.S.A.,” Sanders said in September. “But what happened the day after he was elected? Essentially, in so many words, he said, ‘Thank you, America, for electing me. I’ll take it from here.’ ”

We can be confident that Obama knows about these criticisms, and similar ones that Sanders has made. In his conversation with Thrush, Obama didn’t refer to them explicitly, but he issued a pretty withering assessment of the Sanders phenomenon:

Well, there’s no doubt that Bernie has tapped into a running thread in Democratic politics that says, Why are we still constrained by the terms of the debate that were set by Ronald Reagan thirty years ago? Why is it that we should be scared to challenge conventional wisdom and talk bluntly about inequality and be full-throated in our progressivism? And that has an appeal and I understand that. I think that what Hillary presents is a recognition that translating values into governance and delivering the goods is ultimately the job of politics, making a real-life difference to people in their day-to-day lives.

Translation: Bernie is a dreamer, Hillary is a doer. In case anybody missed the point, Obama later repeated it, in slightly different form:

I think that if Bernie won Iowa or won New Hampshire, then you guys are going to do your jobs and you’re going to dig into his proposals and how much they cost and what does it mean, and how does his tax policy work. And he’s subjected, then, to a rigor that hasn’t happened yet, but that Hillary is very well familiar with.

Was the President, in making these comments, being wholly fair to Sanders, his supporters, and his program? I don’t think that he was. But we can only assume that Obama wasn’t trying to be fair—he was trying to persuade Democrats to back his preferred candidate. And he was also acknowledging an uncomfortable reality: Sanders doesn’t merely represent a threat to billionaires and multi-millionaires. The Vermont senator is challenging the entire Democratic Party establishment, of which Obama, the President, is a part.