His rise is now stirring growing anxieties among some of his biggest detractors, who maintain that his white knight pledges should not insulate him from critiques and what they consider a standard vetting process.

“He has a long history of big-money self-promotion, but he wants to play senior statesmen and try to get people to believe he’s just taking one for the team,” said Zephyr Teachout, a law professor who has run for statewide office in New York and is aligned with Bernie Sanders.

“But he’s spending hundreds of millions because he wants the most powerful job in the world, and he needs the full treatment,” she added, pointing to his positions on foreign policy and Social Security and his long mayoral record.

Bloomberg has risen steadily in national polls, surpassing Pete Buttigieg and nearly doubling Amy Klobuchar’s standing. On Monday, Bloomberg eclipsed Klobuchar in congressional endorsements, with many of the supporters arguing he’s uniquely positioned to beat Trump in the swing states Democrats need to recapture the White House.

Adam Green, of the Progressive Change Campaign Committee, said he approached the DNC last month to talk about including Bloomberg in future debates. Bloomberg’s polling meets the party’s criteria for inclusion, but his refusal to raise money from outside donors — even in minuscule increments — means he can’t meet the qualifying threshold. Green proposed altering the rules so that Bloomberg would be included.

“Imagine a hypothetical world where Bloomberg bought himself 30 percent and he’s the frontrunner in the polls. Would you really not think voters would want to hear what he has to say and see him get some scrutiny on the debate stage?” Green asked.

“I think he’ll inherently get more scrutiny when he’s playing in the same sandbox,” he added. “But there’s still more scrutiny that can come now and voters want it.”

Any rule change would likely spark a wave of criticism from supporters of former candidates who failed to qualify for the most recent debates, including Cory Booker and Julián Castro. Bloomberg has insisted he wants to participate in debates, if only the DNC would drop its fundraising regulation. He has never taken political contributions, including during his three terms as mayor — and said he won't start now.

Bloomberg has dispatched top aides to appeal to the DNC for a change in the rules that would allow him to participate, three sources familiar with the effort said. It’s unclear whether that would happen anytime soon. But the sources were confident the DNC will ultimately agree, so much so that Bloomberg has been participating in debate prep at his midtown Manhattan headquarters.

The campaign declined to comment on internal debate deliberations. The DNC did not respond to a request for comment.

"Mike has been in public life for the past two decades and is aggressively campaigning in states across the country so that voters can hear directly from him about how he'll get it done as president," a Bloomberg spokesperson said in a statement. "As we've said before, Mike would be happy to debate if the DNC changes its rules."

Even with his record ad spending, which reached $270 million on Monday, aides to rival candidates have sought to diminish Bloomberg’s chances in the race. State-by-state polling beginning with Super Tuesday shows he is far from amassing a meaningful share of delegates. A run of victories by any of the top contenders in the four early states could reduce him to a deep-pocketed promoter.

But activists from California to Colorado to Virginia said they can’t ignore the scores of organizers he’s hired to build momentum for himself.

“We have seen rich people run before, but the amount of money Bloomberg is able to throw around is able to get him over the absence of enthusiasm because it’s orders of magnitude” greater, said Neil Sroka of the progressive group Democracy for America.

Sroka, who lives outside Detroit in Wayne County, recently spotted his first candidate representative at a local community meeting: It was a Bloomberg organizer trying to recruit attendees to an office opening.

“It’s starting to filter beyond the nonstop ads,” he said. “These aren’t people parachuting in. They are organizers who have experience, want to get paid a good sum of money and know who the local movers are.”

Bloomberg, at the same time, is running on his own terms. He received an extension to file his personal financial disclosure forms until March 20, more than halfway through the delegate race and after Super Tuesday, which is key to his electoral strategy. He has not released his tax returns. And he has not joined other candidates at forums, or taken scores of open-ended voter questions at town halls like they have.

“He’s trying to bull rush everything with his power, driven by money,” said Murshed Zaheed, a partner at the consulting firm Megaphone Strategies who served as an aide to former Sen. Harry Reid and now backs Warren.

When Bloomberg entered the race, Warren and Sanders both accused him of trying to buy the election. Sanders held him up as the poster child for the Citizens United court decision on money in politics that the Vermont senator wants overturned. But Sanders predicted at the time that Bloomberg wouldn’t get very far.

Warren condemned Bloomberg on his own network, even buying an ad on Bloomberg TV directly taking him on. In a tweet thread last week, she highlighted a news story about a complaint to the Federal Election Commission by Bloomberg's 2001 mayoral opponent, Mark Green, alleging biased coverage by Bloomberg News. Warren called on Bloomberg to lift its ban on reporters investigating Democratic presidential candidates and divest from the company altogether.

In response, Bloomberg’s campaign manager, Kevin Sheekey, tweeted a Bloomberg News story that analyzed how Bloomberg has offered few details to back up his trillions in proposed spending. “Paging Elizabeth Warren,” Sheekey wrote in his tweet.

None of the arguments against Bloomberg are novel. New York City's class of left-leaning Democrats have long chafed over the advantages they believe his vast fortune and broad network of media executives have afforded him.

Mayor Bill de Blasio, who has yet to stop running against Bloomberg's record seven years into his own tenure, told left-wing online show The Young Turks in November, "I think a lot of media outlets were literally worried he might buy them some day and I think a lot of the leaders in those media outlets did not want to make waves or alienate him."

Monica Klein, a progressive consultant in New York who is unaffiliated with a presidential campaign, cautioned against the focus on the novelty of his campaign.

“As mayor, Mike Bloomberg spent years keeping Republicans in power in New York — yet most voters just know him as this bizarre billionaire who gives out iPhones like candy," she said, in response to a story last week about his lavish campaign spending.

Klein thinks it’s time to engage before it’s too late.

“Last election, voters and pundits alike treated Trump with kid gloves because he was seen as an unelectable amusement,” she said. “There’s a word for people who keep doing the same thing over and over again and expecting different results.”