Joseph R. Biden Jr. speaks with Elizabeth Warren about once a week. They review the latest developments on the Covid-19 crisis and the collapsing economy. They trade ideas about how a Democratic president, like Mr. Biden, might rescue the country. They exchange tales about their lives sheltered in place, he in Wilmington, Del., and she in Cambridge, Mass.
Mr. Biden and Ms. Warren are members of the same generation, Democrats shaped by modest upbringings who became United States senators and candidates for their party’s presidential nomination. But with Mr. Biden now actively considering Ms. Warren to be his running mate, it’s their ideological differences — and whether they can build a complementary, productive relationship — that will ultimately determine whether she emerges as No. 2 on the ticket.
Their recent conversations have become a critical quest to find common ground and measure whether they have moved beyond their policy disputes of the past 20 years. Mr. Biden, the presumptive Democratic presidential nominee, is a political moderate, a former vice president and a deal-maker who believes in the bipartisan promise of Washington. Ms. Warren is a liberal from Massachusetts, a former Harvard Law School professor as likely to throw a bomb as to shake a hand in Congress, who has clashed with Mr. Biden on issues ranging from bankruptcy law to the future of Obamacare.
Should Mr. Biden select Ms. Warren, the Democratic ticket would be a marriage of contrasting policy ideas and governing philosophies unlike any seen since Jimmy Carter, the moderate governor of Georgia, chose Walter F. Mondale, the liberal senator from Minnesota, in 1976. And some Democrats are arguing that might be precisely what Mr. Biden needs as he tries to unseat President Trump — particularly at a moment when the country’s deep economic despair could demand bold action of the type Ms. Warren pushed for during her candidacy.
“Having a good team means you should have people who are not the same on everything,” said Harry Reid of Nevada, the former Senate Democratic leader, who is close to both Mr. Biden and Ms. Warren and who has stayed publicly neutral in the process of choosing a running mate. “The fact that they are ideologically different is a plus, not a minus.”
Mr. Biden has not said when he will announce his decision. But Ms. Warren and two other female senators who also competed for the party’s nomination, Kamala Harris of California and Amy Klobuchar of Minnesota, are at the top of Mr. Biden’s list, according to Democrats close to the selection process.
Ms. Warren has not made a secret of her interest in the position, sending signals even before she formally dropped out of the presidential race in February. She answered “yes” without hesitation when Rachel Maddow asked her on MSNBC in April if she’d accept the offer. And she has been calling former President Barack Obama to make clear her eagerness to do what she can to help Mr. Biden.
Mr. Biden, aides said, admires Ms. Warren’s intelligence and her command of domestic policy, particularly economic issues. He thinks she would be a political asset in a campaign, given the passion of her supporters and an ideological résumé that might reassure more liberal Democratic voters who remain skeptical of Mr. Biden’s record of moderation and conciliation.
But the very qualities that made Ms. Warren such a strong force in Congress and on the campaign trail — her independence, her critical thinking and her reputation as a tough fighter — have raised concern among some Democrats, including some in Mr. Obama’s circle, about whether she would be the loyal lieutenant that Mr. Biden was for the former president.
“Biden is not going to pick somebody unless he’s got 100 percent confidence that they’re on the program; that is so key to this,” said David Plouffe, who was Mr. Obama’s senior adviser in the White House. “That person down the hall can’t have any other agenda but to make your administration a success. Biden was that for us.”
Mr. Plouffe said he was confident Ms. Warren would meet that test.
Credit…Ruth Fremson/The New York Times
Mr. Reid said Ms. Warren, as a senator, was independent but not defiant. “As liberal as she is, she never once created a problem for me in the caucus,” he said.
In a sign of Ms. Warren’s willingness to demonstrate flexibility, an aide said that if asked to do so, whether or not she was on the ticket, she would drop her opposition to high-dollar fund-raising, which she made a calling card of her campaign last year. She has also moved closer in line with Mr. Biden on health care, saying that the first priority should be strengthening the program passed under Mr. Obama. For his part, Mr. Biden embraced Ms. Warren’s call to forgive student debt for low- and middle-income families.
This week, in a chummy display posted on Twitter by Mr. Biden’s campaign, Ms. Warren made a joint appearance with the former vice president online to call supporters.
Over the course of nearly 20 years, the relationship between these two high-profile Democratic leaders has been marked by battles and détente. They faced off when Mr. Biden championed an overhaul of bankruptcy rules in the Senate in the early 2000s. She accused him of being too protective of his home state’s banking industry with a law that would disproportionately hurt women.
Their differences were evident in this presidential campaign as well. Mr. Biden dismissed Ms. Warren’s pledge to provide universal health insurance, pressing her to provide details on how she would pay for it.
And it is not only their ideological differences: The two have different styles in their approach to government. That was on display when the two served in the Obama White House and Ms. Warren, as a special adviser to Mr. Obama, pressed for the creation of the Consumer Financial Protection Bureau.
“Vice President Biden spent many years in the Senate and is very attuned to what can be done and where the votes are,” said Richard A. Cordray, who served as the first director of the bureau. “Elizabeth is someone who is willing to stretch the existing process and see what more can be done with it. I think Senator Biden may have learned about that from seeing her in action.”
This would not be the first time Mr. Biden considered Ms. Warren as a running mate. In 2015, the two had lunch at the Naval Observatory, the vice-presidential residence in Washington, where he suggested he would like her to be his running mate if he entered the presidential race. Associates said that Ms. Warren was excited by the prospect, but Mr. Biden ended up not running.
When Hillary Clinton became the Democratic nominee that year, Ms. Warren’s name re-emerged as a potential vice president. Adam Jentleson, a senior adviser to Mr. Reid, drafted a memo with arguments that the senator, who supported Ms. Warren as the best choice, could make in her favor — arguments that her supporters echo today.
“Choosing Warren would unify the party and be seen as a bold stroke of leadership,” Mr. Jentleson wrote at the time. “Warren can attack Trump more effectively than anyone, freeing Clinton to rise above the fray. Trump will win any fight with a male VP, but he cannot handle attacks from women.”
As a political calculation, Ms. Warren could help Mr. Biden reach out to liberal Democrats who consider him too moderate, and women made uncomfortable by an allegation of sexual assault directed against him by a former aide in his Senate office, which he has denied. A CBS News poll this month found that Ms. Warren was the first choice of a plurality of Democrats to be Mr. Biden’s running mate.
But there are liabilities in choosing her, not least the crucial battle over control of the Senate. Were Mr. Biden to win, and there was no change in state law, Massachusetts’s Republican governor could appoint her temporary successor — presumably also a Republican — costing the Democrats a seat. And Ms. Warren would be 74 in 2024, so she’s not an obvious generational successor to Mr. Biden, who is 77.
She could also open up the ticket to the charge that it was too far to the left, and out of step with some moderate voters. And the two of them would have to reconcile the differences they expressed in the primary to present a ticket of unity in a general campaign.
Whether their ideological difference matters should they win the White House is hardly clear. It is unlikely that much of Ms. Warren’s agenda, such as expanding health insurance to cover all Americans, could win approval in Congress. “She’d probably like him to go further left than he plans to go,” said Barney Frank, the former Democratic congressman from Massachusetts who worked with both of them in Congress. “But he’s not going to be able to go as left as he’d like to go.”
Still, there is resistance to Ms. Warren from a number of the party’s most generous donors, especially those in finance industry, who are uneasy about her views.
“She’s smart and talented but I think putting her on the ticket will alienate anybody in the middle,” said Marc Lasry, a New York-based hedge fund executive who prefers Ms. Harris.
As the depth of the economic destruction from the virus becomes clearer, and the scale of the rebuilding ahead grows more sobering, a number of Democrats argued that Ms. Warren’s experience and intellect could prove appealing to Mr. Biden.
“The more serious the situation becomes and the more monumental our challenge is going to be, the better the argument for a partner who has big ideas and capacity to make things happen,” said Shailagh Murray, a top adviser to Mr. Biden when he was vice president.
Mr. Biden himself, in a recent interview on Snapchat, seemed to hint at his desire for a formidable lieutenant.
“I’m looking for someone who has strengths that I don’t have as much,” he said. “I’m not afraid to go out and find someone who knows more than I know about a subject.”
Glenn Thrush contributed reporting.