WASHINGTON — Michael Bloomberg may be absent from the early-state ballots, but behind the scenes, he has been using his wealth and influence to undermine the rest of the Democratic field.

As the other candidates for the Democratic presidential nomination trudged through Iowa and New Hampshire in the early weeks of this year, Bloomberg, the former mayor of New York, has doubled his planned spending on television ads, expanded his staff several times over and started aggressively courting key party influencers — including many who have endorsed top rivals like former Vice President Joe Biden.

Bloomberg could escalate his efforts even more directly after the results of Tuesday's New Hampshire primary are in and as candidates, party insiders and voters begin to reassess the state of the race.

On Friday, in a townhouse across from the Capitol complex in Washington, top Bloomberg campaign advisers huddled with about 20 House members to deliver a briefing on their strategy to win the nomination and defeat President Donald Trump.

The cross section of lawmakers, representing the Blue Dog Coalition, the Congressional Hispanic Caucus and the Congressional Black Caucus, included both members who have endorsed other candidates and members who remain undecided, according to a person familiar with Bloomberg's operation.

The strategy is to keep potential allies informed of Bloomberg's plans in case they decide to sign on later, the person said.

The session on Capitol Hill, the first of several planned by Bloomberg campaign co-chair Stephanie Murphy, a Democratic representative from Florida, came at a time when many Democratic establishment figures are increasingly concerned that the party does not have a candidate who can both stop Sen. Bernie Sanders, I-Vt., from winning the nomination and defeat Trump.

"Last week, I pulled together a group of Members to hear from Bloomberg 2020 senior staff who outlined Bloomberg's path to victory, and many of these members saw what I saw: that Mike Bloomberg is the only candidate with the money, message, and machine to defeat Donald Trump and retake the White House," Murphy said in a statement to NBC News.

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"I anticipate Mike's support from House Democrats will only continue to grow as this process moves forward and as more Members recognize that Mike Bloomberg will get it done."

The event hosted by Murphy is just one of many indications that Bloomberg's operatives are quietly creating a national network of political and community influencers to help him build support on the ground in crucial battleground states while he blankets airwaves with television ads.

"It's been really interesting how he has identified the notes of influence in a unique way where it's not just the big names in households, but it's the big names in households at regional levels," said Maria Teresa Kumar, CEO of Voto Latino. "And that's smart. It's a smart strategy."

Kumar pointed to Bloomberg's outreach to local officials, such as former Philadelphia Mayor Michael Nutter and former Miami Mayor Manny Diaz, as examples of his outreach to influential local leaders.

"I have never seen someone lock in so much talent this quickly. People will try to say that it is money, but I would actually venture to say that he had the 'Mayor University,'" Kumar said, referring to the mayoral training program Bloomberg sponsors at Harvard University. "He has their trust in a way, because he has worked with them closely."

Diaz initially supported Biden, telling The Miami Herald in September that he was going to "do everything within my power to help the vice president." He endorsed Bloomberg shortly after he entered the race.

Last month, actor Hill Harper, who plays Dr. Marcus Andrews on ABC's "The Good Doctor," invited Bloomberg advisers to his home in Detroit to discuss the former mayor's controversial stop-and-frisk policing policy. For some black community leaders and voters, the policy is an obstacle to supporting Bloomberg's presidential ambitions.

The aides said Bloomberg, who apologized for the policy last year, developed stop-and-frisk out of a concern for the disproportionate effects of gun violence on communities of color, according to Matt Marks Evans, a construction executive who attended the Detroit meeting.

The campaign advisers told the attendees that Bloomberg's worry led to enhanced security measures, which created disproportionate enforcement in communities of color — an unintended consequence, they said — and that Bloomberg would not repeat the mistake if he returned to a position of executive power, according to Evans.

A Bloomberg spokeswoman in Michigan did not reply to NBC News' questions about the event and Bloomberg's broader plans to court influencers in time for publication of this story.

Evans, who is supportive of Bloomberg, noted that "there was pushback" in the room, but he and a second source who spoke to participants said the Bloomberg operatives were able to win over some skeptics.

That's because "he's not denying it. He's taking ownership of it," Evans said.

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The meeting at Harper's house served to lay groundwork for Bloomberg's rally in Detroit last week, where Wayne County Executive Warren Evans, Evans' brother, who has yet to make an endorsement in the presidential campaign, introduced the former mayor.

Tavia Galonski, an Ohio state representative, said she's seen Bloomberg campaign officials at three fundraisers for state legislators in the past month, including one held for a political action committee tied to House Minority Leader Emilia Strong Sykes two hours by car from the state capital.

"They were suddenly not just in Columbus, but in Akron," Galonski said.

"They were super pleasant, just working the room," added Galonski, who supports Biden but said she was not asked by the campaign to make a switch to Bloomberg. "They just made it very clear who they were."