In his announcement video, Mr. Biden’s opening argument to Democratic voters and the country at large attempted to set him above and apart from his party’s ideological dividing lines. There was no talk of policy in the video, despite the importance of issues to many Democrats and liberal activists, or even of Mr. Biden’s political record and biography. It was instead a thematic attempt to define the Democratic primary in terms of a question: which candidate can beat Mr. Trump and restore normalcy.
Mr. Biden will seek to make the case for himself in the coming days, giving his first television interview on Friday on ABC’s “The View,” where he memorably appeared in 2017 and comforted a co-host, Meghan McCain, a daughter of Senator John McCain, about her father’s battle with brain cancer. He is also set to campaign in Pittsburgh on Monday.
His long-awaited entry effectively completes the field of major Democratic candidates, and may goad the party’s large number of would-be presidents to compete more aggressively for attention in a race currently framed by two outsize political characters in their eighth decades of life — Mr. Biden and Senator Bernie Sanders of Vermont.
Mr. Biden’s rivals have taken encouragement in recent weeks from signs of unsteadiness and indecision in his camp. Mr. Biden spent much of this month attempting, in fits and starts, to address a wave of stories in which women described his physical manner as discomfiting and excessively intimate. And his advisers have repeatedly explored and then disavowed a range of offbeat or daring plans, including announcing a running mate early in his campaign — perhaps Stacey Abrams, the Georgia Democrat — or kicking off his campaign in Charlottesville, Va., as a rebuke to Mr. Trump for his handling of a 2017 white supremacist rally there.
It is unclear how bold a campaign Mr. Biden intends to run, and whether he will seek to electrify the Democratic coalition or merely satisfy its thirst for a champion who appears up to the job of beating Mr. Trump.
Mr. Biden is also expected to face intensive scrutiny of his decades-long political record as vice president and a Delaware senator, and his political allies believe he must take steps in short order to articulate publicly how his views have changed over time on fundamental Democratic concerns involving race and women’s rights. He has yet to allay concerns about the most contentious aspects of his career, including his treatment of Anita Hill during the confirmation hearings of Justice Clarence Thomas.