The Minnesota congressman made his presidential bid official in New Hampshire before a crowd of a few dozen people composed largely of journalists and campaign staff.On the last possible day to do so, Representative Dean Phillips of Minnesota walked into the New Hampshire Statehouse on Friday through a side door and submitted paperwork to put his name on the state’s primary ballot.He then went downstairs to the visitors center, where he placed a pin for his newborn presidential campaign on a wall of historical campaign pins next to Hubert Humphrey, whom he called “my hero,” and removed a pin featuring former President Donald J. Trump from his desired spot to do so.“By the way, this is a metaphor,” he joked.Then the Democrat walked out into an unseasonably warm morning, stood at a lectern in front of a crowd of a few dozen people, composed largely of journalists and campaign staff, and formally declared that he was challenging President Biden.It was, he acknowledged to reporters earlier, the longest of long shots. Mr. Biden’s re-election campaign has the near-unanimous support of Democratic leaders, who are less than pleased to see Mr. Phillips running. And with the first primaries only about three months away, the hour is late. He has already missed the filing deadline to appear on the ballot in Nevada, an important early-voting state.“I’m at a massive disadvantage,” he said, before citing the Miracle on Ice in the time-honored tradition of underdog candidates everywhere. “This is the country of long shots.”Mr. Phillips — a onetime Biden ally who has repeatedly praised the president even as he says he shouldn’t run again — has made no secret of the animating principle of his campaign: Mr. Biden’s 80 years of age, and what he sees as his party’s refusal to grapple with voters who have, in survey after survey, expressed significant concerns. In remarks making his bid official, Mr. Phillips, 54, called for generational change, warning of dire electoral consequences should the party refuse the debate he hopes his candidacy will force.Mr. Phillips filed paperwork to put his name on the New Hampshire primary ballot with Secretary of State David Scanlan on Friday.Reba Saldanha/Reuters“It is time for the torch to be passed to a new generation of American leaders,” he said.Among the sparse crowd in front of the statehouse in Concord, N.H., were some who agreed.Tracy Tanner Craig, 49, of Peterborough, N.H., said that while she generally voted for Democrats in national elections, she had been disillusioned with the party since the Great Recession. She and her husband, Matt Craig, 51, heard about Mr. Phillips five days ago, immediately began researching him and liked what they saw.“Age matters,” Ms. Tanner Craig said, expressing dismay that her two children — who, for the first time, are both eligible to vote in a presidential election — might have to choose next November between an 81-year-old, Mr. Biden, and a 78-year-old, Mr. Trump. “What hope does that give them for a future? What inspiration is there? Last time we felt inspired was ’08 with Obama.”She and Mr. Craig said they liked that Mr. Phillips was moderate, and did not like that Democrats had largely circled the wagons around the incumbent. (Mr. Biden will technically not appear on the New Hampshire primary ballot.)“We need options,” she said. “Part of democracy is we should have choices.”“Good candidates, a diverse set of candidates,” Mr. Craig added. “Instead of, ‘OK, we’re going with Trump again,’ ‘OK, we’re going with Biden again.’”Dan Kipphut, 66, of Concord, said Mr. Biden “should take the last four years as a big win and move on.” He has done “pretty well,” Mr. Kipphut said, but “I think the country could stand to have some new direction with a new generation.”Others were there simply out of curiosity — willing to consider Mr. Phillips, but not sure they supported him yet.“Considering all of the other stuff happening, I think he’s doing somewhat of a good job,” Nick Hadshi, 32, of Concord, said of Mr. Biden. “It could be better, it could be worse.”He was open to alternatives, he said.Mr. Biden’s campaign said in a statement that it was “proud of the historic, unified support he has” and added: “The stakes of next year’s election could not be higher for the American people, and the campaign is hard at work mobilizing the winning coalition that President Biden can uniquely bring together to once again beat the MAGA Republicans next November.”While Mr. Phillips outlined a number of issues that he would focus on — including the affordability of health care and child care, and the accessibility of guns after the mass shootings in Lewiston, Me., this week — he did not cite any policy disagreements with Mr. Biden. He did, however, mention disagreements with some of his fellow Democrats in general and suggested, without elaborating much, that they saw issues as too black and white.“Two things not only can be true at once, they usually are true at once,” he said. “We need border security, and we need immigration reform. It’s humane, and it’s the economic choice. Every issue, from gun violence prevention to reproductive rights to any policy of substance we need right now — every one of them, two things are true at once.”Mr. Phillips told reporters that he saw preventing Mr. Trump from winning the 2024 election as an “existential” necessity, and that this was why he was running. But he also said unequivocally that he would fall in line if Mr. Biden won the primary.“If you care about democracy, if you care about freedom, I think it’s terribly important that a Democrat win this election,” he said. “And I will do anything, I will give everything I have, every moment of my time, every ounce of my energy, to ensure that that nominee — whether it be me, of course, President Biden or somebody else — becomes president.” More