President Biden is set to ask for another four years in office as soon as Tuesday, four years after declaring his 2020 candidacy in the hopes of preventing President Donald J. Trump from “forever and fundamentally” altering the character of the United States. People close to Mr. Biden expect him to announce his re-election bid in a video, much the way he entered the last campaign, when he used the same format to urge Americans to embrace a different vision for the country and to “remember who we are.” “I told you I’m planning on running,” Mr. Biden said at the White House on Monday, in response to questions from reporters. “I’ll let you know real soon.” Mr. Biden’s mission will be more complicated the second time around, as he is forced to defend his record while warning about the dangers of Mr. Trump’s return. While the former president remains the front-runner for the Republican nomination, Gov. Ron DeSantis of Florida is also preparing for a likely bid. Within days of Mr. Biden’s expected announcement, some of his top donors have been invited to gather in Washington for a financial summit of sorts that will kick off a race against time to fill the president’s war chest. The meeting, expected to be on Friday, will be a necessary early step in a campaign process that will remain low-key for as long as a year. That will be quickly followed by Mr. Biden hiring a staff that can work outside the White House: a campaign manager, communication aides, state campaign directors, pollsters, finance managers, volunteers and more. Among those being considered to run the re-election campaign is Julie Chávez Rodriguez, a senior White House adviser and the granddaughter of Cesar Chavez, the American labor leader. But one person familiar with the president’s thinking said that as of Sunday afternoon, Mr. Biden had not made a final decision on who would run the campaign day to day. Regardless of that choice, Mr. Biden’s kitchen cabinet of advisers is clear: The handful of people whom he has kept close throughout his first bid for the presidency and his time in office. That includes Mike Donilon, his top political adviser; Anita Dunn, his communications guru; Steve Ricchetti, his legislative adviser; Ron Klain, his former chief of staff; Jen O’Malley Dillon, who managed his first campaign and is now a deputy chief of staff in the White House; and Kate Bedingfield, his former communications director. That team is betting that Mr. Biden’s accomplishments will win him the votes to remain in the Oval Office. He will argue that he has restored prosperity despite lingering economic uncertainty and concerns about inflation. He will focus on the passage of legislation to pump billions of dollars into infrastructure, climate and health care. And he will take credit for restoring alliances abroad at a time of global tensions. The president will also seek to sharpen the differences with what he describes as an elitist, intolerant Republican Party that will threaten the progress his administration has made. As he begins to ramp up his campaign, he is hoping to demonstrate that the choice for voters is between a competent president and a return to the chaos Mr. Trump embraced. “When you’re a president running for re-election, you’re the obvious and fair target for anyone who’s disappointed not just by the amount of progress, but even the speed of that progress during your time in office,” Jen Psaki, Mr. Biden’s former press secretary, said on her MSNBC show on Sunday as she discussed the impending campaign announcement. “Running for the president the first time is aspirational. You can make all sorts of big, bold promises,” she said, predicting an “incredibly difficult” re-election campaign for Mr. Biden. “Running for re-election is when you actually get your report card from the American people.” That report card will include some low marks from voters that the president and his team will have to confront as they build a campaign operation that is likely to be run out of Wilmington, Del. — close to the president’s regular weekend getaway over the past two years. At 80 years old, Mr. Biden is the oldest president in American history, and polls suggest that even most Democrats are concerned about re-electing a commander in chief who would be 86 by the end of his second term. The president must also answer for his administration’s chaotic handling of the US withdrawal from Afghanistan after 20 years of war and the rapid inflation that has driven up costs of everything from groceries to gas, eating away at the economic fortunes of most middle-income Americans. But the people charged with delivering another win for Mr. Biden inside the White House and in the nascent campaign are determined to try to keep the focus on the alternative. The president has begun ramping up his anti-Trump rhetoric, accusing the Republican Party of embracing a “radical, MAGA agenda,” repeatedly using the acronym for the “Make America Great Again” slogan that Mr. Trump used throughout his 2016 campaign and during his presidency. In a speech last week at a union hall in Accokeek, Md., for Local 77 of the International Union of Operating Engineers, Mr. Biden used the MAGA label 21 times as he assailed a Republican proposal in Congress to cut spending on domestic programs by 22 percent. “The MAGA 22 percent cut undermines rail safety, food safety, border security, clean air, clean water,” the president told the small but friendly union audience. “It’s not hyperbole; it’s a fact." People close to Mr. Biden said over the weekend that his decision to formally announce his candidacy would not immediately result in a significant shift in his actions or schedule. He is unlikely to begin campaign-style rallies for many months, said people with knowledge of his plans, who spoke on the condition of anonymity because the president has not yet made his announcement. Instead, Mr. Biden will continue making the same kinds of policy-focused trips that he has for several months. Those trips — including speeches about declining unemployment, the environment, infrastructure improvements and child care — are intended to underscore his administration’s achievements since taking office in the middle of a pandemic-induced economic crisis. Aides have said the president intends to continue delivering those messages as often as possible. Mr. Biden will also continue to focus on the challenges of being president. Next month, he is scheduled to fly to Hiroshima, Japan, for a three-day summit with world leaders that will focus on the war in Ukraine and emerging competition from China and other hot spots around the world. He will then travel to Australia to mark a new agreement on nuclear submarines. When Mr. Biden returns to Washington, he faces a showdown with Speaker Kevin McCarthy over the need for Congress to raise the debt ceiling and avert an economic disaster. The New York Times