Obama privately said he would speak up to stop Sanders from 2020 nomination: Report

Former President Obama has privately said he would speak up to stop Sen. Bernie Sanders from becoming the Democratic nominee, Politico reported.

Obama has steered clear of endorsing a candidate in the 2020 Democratic presidential primary and instead has remained publicly neutral. Politico reported that several of Obama's advisers claim the former president sees his role as "providing guardrails" and working to "unite the party when the nominee is clear."

The only exception would be if "he believed there was some egregious attack" and if it looked like Sanders would win the nomination.

"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," according to Politico.

In 2016, Obama didn't get involved in the Democratic primary until roughly a month before the Democratic National Convention, when he encouraged Sanders to rally behind Hillary Clinton. In June, he announced his endorsement of Clinton. Sanders eventually joined him in his endorsement of Clinton

Sanders isn't the only candidate Obama has been keeping an eye on behind closed doors. He is reportedly "deeply skeptical" of South Bend, Ind., Mayor Pete Buttigieg, and his relationship with Sen. Elizabeth Warren was described by Politicio as "famously complicated." As for his former Vice President Joe Biden, Obama and his advisers have reportedly said he lacks an intimate bond with the electorate, especially in Iowa.

One adviser, who wasn't identified, told Politico he "can't really confirm" if Obama would really go as far as to step in to prevent a Sanders nomination because he "hasn't said that directly to me,"

"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," the adviser added. "But I don't think that's likely. It's not happening."