Former President Barack Obama reportedly told advisers behind closed doors earlier this year that he would actively oppose Sen. Bernie Sanders if the progressive senator from Vermont opened up a big lead in the 2020 Democratic presidential primary race.

"Publicly, [Obama] has been clear that he won't intervene in the primary for or against a candidate," Politico reported Tuesday. "There is one potential exception: 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."

"Obama's post-presidency is grating and full of contradictions. He considers himself a success but the mere fact of Trump's presidency belies this. He won on hope and counsels hopelessness."

—David Klion, Jewish Currents

Progressives viewed Obama's comments as further evidence that the former president, who was elected in 2008 on the soaring promise of "hope and change," is now using his influence on the Democratic Party to undercut the grassroots push for transformational policies like Medicare for All and the Green New Deal.

"Obama's post-presidency is grating and full of contradictions," tweeted David Klion, news editor at Jewish Currents. "He considers himself the leader of the party but refuses to lead. He considers himself a success but the mere fact of Trump's presidency belies this. He won on hope and counsels hopelessness."

One anonymous Obama adviser would not confirm to Politico that Obama "would really lay himself on the line to prevent a Sanders nomination."

"He hasn't said that directly to me," the adviser said. "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."

According to Politico, Obama plans to speak out more frequently about the state of U.S. politics in the coming weeks. Earlier this month, Obama told a roomful of rich donors that he is worried about "certain left-leaning Twitter feeds" and "the activist wing of our party," sparking outrage from progressives.

"Over the next year, Obama, according to his closest advisers, will start to emerge with slightly bolder colors," Politico reported Tuesday. "The boldest might be riding into a battle unfolding on his own side, if he did lead a potential stop-Bernie campaign."

Obama advisers told Politico they don't believe Sanders has a chance to win the Democratic presidential nomination. But recent polling suggests the Vermont senator is experiencing what his campaign described as a "surge."

A Morning Consult tracking poll released Monday showed Sanders has gained nine points in early primary and caucus states since October. Sanders has also jumped back into second place behind former Vice President Joe Biden in Real Clear Politics' national polling average.

For the first time in months, @BernieSanders is back in second place in the @RealClearNews average of recent polls. This is a significant improvement in position for Sanders, who has been rising steadily in recent weeks. pic.twitter.com/ZHPGR2ugnp — John Nichols (@NicholsUprising) November 26, 2019

Obama's position on Sen. Elizabeth Warren (D-Mass.), a 2020 Democratic presidential candidate, has also been antagonistic, according to Politico.

"Back in early 2015, when Warren was considering running for president and started to excite progressives, Obama said privately that if Democrats rallied around her as their nominee it would be a repudiation of him—a clear sign that his economic decisions after the Great Recession had been seen as inadequate," Politico reported. "There are very few former senior Obama officials in Warren's campaign."

David Dayen, executive editor for The American Prospect, wrote last week that Obama's attacks on the progressive wing of the Democratic Party "are music to the ears of the wealthy and powerful."

"This defense of the reigning economic order, originating with the donor class and media allies, with its effective abandonment of the vulnerable and disenfranchised, with nothing for those struggling to make it in a rigged economy, is a recipe for social and political unrest," Dayen wrote. "From lofty heights, Obama has now become a dampener of hope, a barrier to change, and a threat to progress."