WASHINGTON (NYTIMES) - For decades the vice-presidential selection process has had an air of cloak-and-dagger to it. The party's nominees would say little about their thinking, the would-be running mates would reveal even less, and an elaborate game of subterfuge would unfold that mostly captivated political insiders and usually had little bearing on the election.

But a convergence of forces has transformed Joe Biden's search for a running mate on the Democratic ticket. His pledge to pick a woman immediately limited the pool of potential candidates and intensified the competition; that decision, coupled with Biden's garrulous tendency to think aloud about his options, have remade the tryout period into an unusually public audition, and the coronavirus outbreak ensured that it is taking place entirely online and on TV.

And Biden himself has increasingly pushed into the political foreground the overwhelming reason that his choice may be the most consequential in decades: the expectation, downplayed but not exactly denied by the Biden campaign, that the 77-year-old would be a one-term president. If that turns out to be the case, his running mate now could well be leading the Democratic ticket in four years.

"I view myself as a transition candidate," Biden said during an online fundraiser last week, likening his would-be presidential appointments to an athletic team stocking its roster with promising talent: "You got to get more people on the bench that are ready to go in - 'Put me in coach, I'm ready to play.' Well, there's a lot of people that are ready to play, women and men."

The ramifications of Biden's choice will be profound. Even if he loses in November, his decision will all but anoint a woman as the party's next front runner, and potentially shape its agenda for the next decade, depending on if she is a centrist or someone more progressive.

"Joe being 77, I think people are going to look to see who is the person who could be the next president," said Harry Reid, the Democratic former Senate majority leader, calling Biden's decision the most significant "in any election cycle I've seen."

Former Senator Claire McCaskill of Missouri was even blunter about what is at stake: "You're writing your ticket to be the first woman president."

There are other factors that have made Biden's decision so momentous. Tara Reade's allegation of sexual assault against Biden has ensured that whichever woman he selects will be his principal surrogate battling those claims, while leaving many Democrats, men and women, convinced the party must put forward a female nominee in 2024.

And given President Donald Trump's penchant for race-baiting, the disproportionate impact the virus is having on communities of color and the political loyalty of black women, many leading Democrats believe Biden will select a black or Latina running mate.

"It boils down to whether he has a Hispanic woman or a black woman," Reid said.

Biden has been careful to avoid providing a definitive signal on whether he would seek reelection should he win this year. But his references to serving as a transitional figure in the party, and the yearslong public health and economic recovery that the virus may require, have left many Democrats with the belief that, at age 82 in 2024, he would pass the party's torch to his vice-president.

"I don't want to wish ill on anyone, and I love Joe Biden, but we'd be electing somebody in his late 70s," said former Senator Heidi Heitkamp of North Dakota, referring to the November election. She said of the vice-presidential competition: "This is really auditioning to be the next leader of the Democratic Party."

Many Democrats believe a gut politician like the former vice president will pick somebody whose measure he has taken. But that is not to say that Biden, who in recent weeks has reaffirmed his commitment to picking a woman, is immune to political considerations: He will weigh the turnout lift he might get from picking a woman of colour alongside the potential regional upside from selecting a Midwesterner.

Privately, Biden's aides have started to reach out to Democrats who know the contenders to solicit their views. They have also had some party leaders talk directly with the former vice president about how he ought to be thinking about his decision, according to Democrats familiar with the conversations.

Biden himself has talked publicly about potential candidates to an unusual degree. He has chatted with Senator Amy Klobuchar of Minnesota and Governor Gretchen Whitmer of Michigan, and held personal phone calls with Senators Kamala Harris of California and Elizabeth Warren of Massachusetts, who answered bluntly "yes" when asked on MSNBC if she would accept an offer to be Biden's running mate.

Advisers to all four women acknowledge privately that they are keenly interested in the vice presidency.

At the same time, the former vice-president and his top advisers are being heavily lobbied.

Stan Greenberg, a longtime Democratic pollster, has laid out a case to Biden's inner circle that he should choose Warren to consolidate support across the Democratic coalition and drive up turnout among younger people and liberals, according to people familiar with Greenberg's overtures.

A polling presentation Greenberg shared with the Biden campaign cautioned that as of early April, supporters of Senator Bernie Sanders were "dangerously not" united behind Biden's candidacy. Greenberg suggested that a strongly progressive message on the economy would resonate with those people.

The three senators Biden competed against in the primary have vocal advocates in and around his orbit.

But they also have their detractors. Some Democrats worry Warren is too liberal for Biden and point out that choosing her could disrupt the party's prospects to control the Senate given that Massachusetts has a Republican governor who could temporarily appoint her successor. A number of progressives are uneasy about the moderate Klobuchar. And Biden's wife, Jill, has been open about how angry she was over Harris' biting attack on him in the first debate last year.

A number of Biden allies are advocating lesser-known Democratic women. One of his top supporters has made the case to him for Gov. Michelle Lujan Grisham of New Mexico, a Latina who served in Congress and as the state's health secretary, experience that could prove invaluable during a pandemic. Lujan Grisham's sister died of the same cancer that claimed the life of Biden's son, Beau.

Another close friend of Biden has urged the campaign to consider the former national security adviser Susan Rice, a black woman who has never run for office but who has deep governing experience.

Lujan Grisham and Rice have done nothing publicly to pursue the post. In contrast, Stacey Abrams, the former candidate for governor of Georgia, has recently embarked on a sustained media tour to pursue the vice presidency, openly encouraging Biden to choose her in a manner that has startled even some of her admirers.

Whoever gets the nod, Biden officials say, it will not be until this summer. Rep. Cedric Richmond of Louisiana, a chairman of the campaign, said he hoped Biden would wait to make his selection until after both the candidate and the vetting committee he appointed had the chance to interview potential running mates in person.

"I would not want him to make a decision like that without meeting and having some real face-to-face conversations," Richmond said.

Asked about the very public nature of the competition, he said: "The trying-out on TV, I think, is normal. The actual campaigning for it is a little different, but we're in different times and people make their own decisions."