Primary voters here have shown they are largely looking for a more progressive nominee, as Elizabeth Warren and Bernie Sanders dominate in poll after poll. In the latest survey of New Hampshire Democratic voters, the two garnered a combined 40% of support and were the top two most-liked candidates, in terms of favorability. Smith said both were relatively unknown when they first started running for president but have spent years cultivating a following here.

Patrick, speaking to reporters after filing for the ballot, immediately sought to distinguish himself from the rest of the field.

“In many ways, it has felt to me watching the race unfold that we’re beginning to break into camps of nostalgia on the one hand and big ideas — sort of my way or no way — on the other,” he said, in an apparent reference to former Vice President Joe Biden, Warren and Sanders.

Patrick’s strategy is to do well in New Hampshire, then use that momentum to carry him into South Carolina, where another win could catapult him into Super Tuesday. But he acknowledged how hard that would be. He filed here just a day before the deadline, flanked by his wife as he dropped off a $1,000 check.

“If running for president is a Hail Mary under any circumstances, this is like a Hail Mary from two stadiums over,” he said.

While other Democratic hopefuls “have built relationships over the years,” said Jim Demers, a top Democratic strategist who advised President Barack Obama, Patrick “starts from scratch with 90 days to go before the primary.”

His campaign launch was certainly untraditional. Patrick made no apparent attempt to reach out to Democratic activists or the state party’s leadership ahead of his decision. He said he spoke to Obama, his senior adviser Valerie Jarrett and Warren. Patrick said his call with Warren was "kind of a hard conversation for both of us," but declined to elaborate.

There is no precedent for how quickly Patrick will need to assemble and launch a campaign here, said Judy Reardon, a longtime political adviser to Sen. Jeanne Shaheen (D-N.H.). With only three months until the primary, it's too late to take on other campaigns that have spent up to two years building out their organizations, she said. Perhaps Patrick could pull it off if he had tens of millions of dollars to spend, she said, but that's not an option for him.

Indeed, the sheer amount of logistical work needed to catch up is staggering. Patrick’s campaign would need to hire as many as 90 staffers to match the Sanders campaign; rent a dozen office spaces throughout the state to compete with Pete Buttigieg; and make tens of thousands of voter contacts to even begin to approach Warren's outreach. Biden has relationships here going back more than three decades.

“I guess if Elizabeth Warren and Bernie Sanders and Joe Biden and Pete Buttigieg all tank in Iowa, things would be so upended it’s possible,” said Reardon said. But “I really don’t see” that happening.

Patrick’s said he plans to run a campaign focused on healing the country, in the mold of his friend Obama. Speaking to reporters, Patrick even invoked Obama’s campaign line du jour, saying he was “fired up”.

But Booker has tried a similar tack and failed to break out, Smith, the pollster, noted.

“The first thing [Patrick will] have to do is find a message that is going to resonate with voters that is unique to him,” Smith said. “That’s going to be his biggest challenge right now. What makes him different from Cory Booker? What makes him different from any of the other candidates.”

One factor in Patrick’s favor is polling showing that only about 15 percent of New Hampshire voters have settled on a candidate. Another sliver of hope are the former staffers to Beto O’Rourke who recently became free agents when he dropped out two weeks ago and might be available to Patrick.

Abe Rakov, who served as O’Rourke’s early-states director, is now Patrick’s campaign manager. When Patrick fielded a question about the logistics of how he would win, he jokingly turned around, pointed to Rakov and jokingly said, “Talk to him.”

"We're going to compete in Iowa and everywhere else, along with New Hampshire and South Carolina," Rakov said.

Patrick called Iowa Democratic Party Chairman Troy Price on Thursday to talk about his entry in the race and indicated he’d be visiting the early caucus state next week, Price said. Troy said the two had a “good conversation” and he told Patrick, “The water is warm in Iowa.”

Another former O’Rourke staffer, Wyatt Ronan, was spotted assisting Patrick with the crush of media inside the cramped inside the secretary of state’s office. Ronan is a well-respected operative who worked for both the state party and Rep. Chris Pappas (D-N.H.) before becoming O’Rourke’s local communications director.

Two others on the market are Mike Ollen, who was political director for Sen. Maggie Hassan (D-N.H.) before going on to serve as New Hampshire state director for O’Rourke, and Rob Friedlander, who served as O’Rourke’s national communications director and also has extensive New Hampshire experience.

Several field organizers who were let go by Sen. Kamala Harris’ campaign when she essentially gave up on New Hampshire earlier this month are also looking for jobs. Other aides from Patrick's time as governor were also seen around him Thursday.

As much as local political operatives don't see a path for Patrick, they did offer him some advice in keeping with New Hampshire tradition: Don’t spend a minute thinking about Iowa, devote every waking minute to campaigning here and figure out a message to pick off support from moderates Biden and Buttigieg.

“To win New Hampshire, he’s just got to make sure he has a (toll) transponder working because he’ll be traveling up to New Hampshire a lot,” said Kathy Sullivan, a state Democratic party official. “It’s going to take a lot of resources, he’s got to do a lot of mail, he has to do a lot of TV, and he has to be here doing town halls.”

Patrick has not maintained relationships with party officials, they said. Party Chairman Ray Buckley, who is celebrating his 60th birthday in Puerto Rico, said Patrick called him Thursday morning to wish him a happy birthday.

“Today is a big day for both of us!” Buckley tweeted.

Patrick also called Hassan, who served as governor of New Hampshire when he was governor of neighboring Massachusetts. They were not able to connect.

Though Massachusetts shares a media market with New Hampshire, Patrick has been out of office for nearly five years and will need to reintroduce himself.

As governor, he gained fanfare here for helping to negotiate an end to a labor dispute that re-opened a much-beloved grocery store chain. But that was in 2014.

His proximity to the state is an advantage and disadvantage, said several strategists. Being able to drive an hour north on Interstate 93 will make it easier for him to meet voters, especially compared to campaigns wholly focused on Iowa, like Harris’. But his neighbor-state status also raises expectations for him here.

“I think someone is not serving him well here,” said a senior Democratic advisor who has won a number of campaigns here but asked not to be named to speak frankly. “He won’t be able to out-raise [other Democrats], he won’t even be on the debate stage and he’s been out of office for years now, so it isn’t even like he’s fresh.”

But Patrick said most voters haven't tuned in yet. He asserted that it wouldn't make a difference whether he'd been campaigning in the state for years or weeks.

“My ability to win this isn’t dependent on me,” he said. “It’s dependent on the voters and they haven’t made up their mind.”

Stephanie Murray and Natasha Korecki contributed to this report.