Two of the Senate’s highest-profile progressives are attracting presidential speculation — again. 

Roughly two years after Sens. Bernie Sanders (I-Vt.) and Elizabeth Warren (D-Mass.) suspended their White House bids to back Joe Biden as the party’s nominee, they are getting attention for what some Democrats say resemble early national campaigns-in-waiting.

Neither senator has announced another bid or even come close to it. They’ve faithfully backed the president’s agenda, worked the halls of Congress and said they want to see him thrive. 

But as Biden’s approval rating fails to crack the low 40s, Sanders and Warren — who are both up for reelection in 2024 — are pushing him in new ways, raising questions about their own maneuvers in the process. 

“No one really knows if Biden is going to run or not run,” said Cooper Teboe, a donor adviser to progressive candidates. “People are trying to stake claim if he does not.”

This week, a top Sanders adviser raised the possibility that Sanders could mount a third bid for the White House, a scenario that seemed nearly unfathomable when he quickly endorsed Biden’s nomination against former President Trump.

In a memo circulated on Wednesday, former Sanders campaign manager Faiz Shakir answered a hypothetical question from a supporter about whether Sanders would consider running if Biden does not seek a second term. 

“In the event of an open 2024 Democratic presidential primary, Sen. Sanders has not ruled out another run for president, so we advise that you answer any questions about 2024 with that in mind,” Shakir wrote.

The memo, first reported by the Washington Post and confirmed by The Hill, sent shockwaves through Democratic circles and made some progressives’ ears perk up.

“I was heartened to see that Sen. Sanders and his progressive message still resonates so strongly with the vast majority of Americans,” said Stacey Walker, a political organizer from Iowa who received the memo as a staunch supporter. 

Some in Sanders World praised the move as good politics.

“There’s no question it’s smart,” said one left-wing operative close to the senator’s orbit about the memo’s conception. “You have to do that.”

To be sure, Biden has given no indication he doesn’t intend to run again. The White House has repeatedly brushed off such speculation, and earlier this week, The Hill learned from two sources that Biden had told former President Obama he intends to campaign in 2024. 

But while not too long ago Biden was all but guaranteed the 2024 nomination, things may not be so settled anymore. 

The trajectory of his presidency continues to concern Democrats who fear his low approval rating will hinder the party’s chances of staying in power and possibly his own. If that happens, Biden’s fate is considerably less certain, those voices say.

Sanders had all but ruled out a third presidential campaign after coming up short against Biden and former Secretary of State Hillary Clinton in 2016. In May, he was explicit: “It’s very, very unlikely that I’ll be running for president ever again.”

Some close to the senator take him at his word about his intentions. They believe chatter about his national prospects to be premature, nonserious or misguided. 

“This is a way for his team to keep him in the conversation,” said Chuck Rocha, who was a senior adviser for Sanders’s 2020 campaign. “If not him, others are already starting to plan and look.”

Talk about a possible progressive replacement to Biden is not new. 

It started in earnest when negotiations around Build Back Better, his expansive social spending and climate package, failed because of two moderate Democrats. Progressives were aghast when Sens. Joe Manchin (D-W.Va.) and Kyrsten Sinema (D-Ariz.) effectively killed in the Senate what the House had already passed.

That anger compounded when Biden also couldn’t convince the chamber’s narrow majority to pass a voting rights bill and then, as the country’s chief executive, declined to use his authority to enact other measures such as student loan forgiveness.

With the midterms now just six months away, Sanders and Warren are pressuring Biden to act more decisively, effectively igniting questions about why they’re criticizing him more harshly now than in the past.

“We can’t govern if we don’t win,” said Walker. “However, in this particular moment, Americans are starting to ask, what use is winning if we refuse to govern when we do?” 

Unlike Sanders, Warren’s moves have been less overt.

That changed this week when she penned an op-ed asking Biden to do more of what he promised before November.  

“To put it bluntly: if we fail to use the months remaining before the elections to deliver on more of our agenda, Democrats are headed toward big losses in the midterms,” she wrote in The New York Times on Monday. She then followed up in an interview with “Pod Save America,” the popular program started by Obama alums. 

Some Democrats said Warren outlined what activists had been long calling for during Biden’s first term.

“She is correct and joins a chorus of mostly progressive activists, thinkers and policymakers who have been singing this song for months now,” said Walker. 

The Massachusetts Democrat has maintained a relatively low public profile since Biden took office in January, save a few bursts of attention. She tried out for the role of vice president and later expressed interest in becoming Treasury secretary, a job allies saw as a wonky and natural fit but was passed over for Janet Yellen.  

She’s since weighed in on key policy debates and appointments, from the Federal Reserve chairmanship to antitrust issues, without much fanfare. More recently, she’s been a leading voice pushing Biden to cancel as much as $50,000 in student loan debt per borrower.

She has also recently lent her name to several down-ballot candidates up this year: Summer Lee in Pennsylvania’s 12th Congressional District, David Segal in Rhode Island’s 2nd Congressional District and Delia Ramirez in Illinois’s 3rd Congressional District. She also endorsed Rep. Anthony Brown (D-Md.) in the state’s attorney general contest.

Those movements, some progressives argue, are signs that the senator is interested in raising her profile. 

“Not just that op-ed,” said Teboe. 

“If you look at her political operation, she’s endorsing in every race she can get her hands on. She’s sending emails out. She’s trying to build political currency in as many states as possible,” he added, stressing that it all hinges on if Biden declines to run again.

As distinct as Warren’s inside-out style has become to her personal brand, Sanders has remained more in-your-face. 

The democratic socialist has publicly sparred with Manchin and Sinema and pushed Biden to go for as much as $6 billion during the early talks around the spending package. As chairman of the Senate’s budget committee, he has expressed frustration with centrists in his caucus who have refused to budge on the same issues that inspired voters to turn out for Biden. 

Sanders made rounds of cable news appearances, each time seeming more dissatisfied with the political reality that Democrats can’t enact things such as a $15 minimum wage or Medicare for All without an overwhelming majority of support.  

“Sen. Sanders clearly conditioned his consideration of another presidential run on an open primary, which of course means President Biden would have determined not to seek reelection,” said Walker. “I think this is admirable.”

Sanders made rounds of cable news appearances, each time seeming more dissatisfied with the political reality that Democrats can’t enact things like a $15 minimum wage or Medicare for All without an overwhelming majority of support. 

He is also increasing his travel schedule, including going to several competitive races with national implications. He’ll be in New York and Virginia over the weekend to express support for employees of Amazon and Starbucks, two of the senator’s biggest corporate targets, who recently formed unions. 

“If we find ourselves in a position where President Biden opts not to run, I imagine Sen. Sanders will feel an obligation to think about stepping up to the plate,” Walker said. “That he would even consider doing so again is a courageous act of patriotism.”