Most of the pool of a dozen or so candidates that are either known or figure to be in consideration divide neatly into those geographical and demographic camps.

Minnesota Sen. Amy Klobuchar, Michigan Gov. Gretchen Whitmer and Wisconsin Sen. Tammy Baldwin are white and hail from the industrial Midwest — all from states that figure to be closely contested. California Sen. Kamala Harris and former Georgia gubernatorial candidate Stacey Abrams are African-American, while Nevada Sen. Catherine Cortez Masto and New Mexico Gov. Michelle Lujan Grisham are Latina.

The former vice president has indicated a preference for candidates who have been vetted by running their own campaigns, including former opponents. He has repeatedly said he wants a partner who can advise him, disagree with him where he’s wrong yet remain “simpatico” with him on major issues even if they may differ at times.

On Thursday, Biden told donors during a virtual fundraiser that he’s heeding President Obama’s advice, who told him to surround himself with people who “know more than you know.” He also stressed the need to have a woman running mate who “looks like America.”

Former Obama campaign aides — as well as top African-American backers of Biden — would prefer Biden pick a woman of color, arguing that it rounds out his candidacy better and has a photo-negative quality to the Obama-Biden ticket, which paired a younger black man at the top of the ticket with an older white man. Here, an older white man would be joined by a younger black woman.

A black running mate, they say, would not just help in Sun Belt swing states like Florida and North Carolina, but also in Great Lakes states like Wisconsin, Michigan and Pennsylvania, which are more often associated with white voters. To win them, Democrats need a good portion of white voters but also stronger black turnout in cities like Milwaukee, Detroit and Philadelphia.

That didn’t happen in 2016, when President Trump flipped all three states.

In the battleground of North Carolina, Democratic Party Chairman and Insurance Commission candidate Wayne Goodwin has a special fondness for the Obama-Biden ticket, which helped sweep him into office in 2008. After winning reelection in 2012, he lost in 2016 when Trump carried the state. He’s now running for a third nonconsecutive term.

“I will be personally pleased and personally thrilled if Joe Biden chooses a black woman as a running mate because black women are the backbone of the Democratic Party,” Goodwin said. “Joe Biden brings his own coalition. But to further energize and maximize the strength of a Biden presidential campaign, it is I think the wisest choice and the best choice to select a woman of color.”

Yet the 46 electoral votes in Michigan, Pennsylvania and Wisconsin that flipped to Trump in 2016 lead many to view a candidate from the industrial Midwest as the best guarantee of success in November.

In Wisconsin, the swing state Trump won by the narrowest of margins, former state party Chairman Mike Tate said he thinks people are underestimating Biden’s existing support among black voters and that his home-state senator, Tammy Baldwin, has shown she “can get white working class votes and turn out the base.” As the first openly LGBT senator, Baldwin can also generate excitement with progressives he said.

“If you see we’re falling behind in the Midwest and that those are going to be the ultimate swing states — the Michigans, the Wisconsins and even Minnesota — then you have to take a second look at a Whitmer or a Klobuchar,” said Moe Vela, a former top aide in the vice president’s office.

The party’s weakness with white working class voters — those without college educations that revealed itself so dramatically in the Midwest — became apparent during Obama’s second midterm election, and were downplayed by party elites, noted Democratic pollster Keith Frederick.

“The 2014 elections were the canary in the coal mine about how much the Democratic Party had run its string out [with many white voters],” he said.

Since Trump is making his strongest play to carry the nation’s biggest swing state of Florida, Frederick said, it might make more sense for Biden to pick a Great Lakes white woman as a running mate to peel off the region’s potential swing-voting women without college degrees, who range in age from young to old.

When Biden launched his candidacy last year, he fashioned himself as the candidate Obama chose in 2008 to appeal to those voters, particularly in the Great Lakes states. And though he initially lost white voters in the first three states during the primary this year — only to have his campaign resurrected and powered by black voters starting in South Carolina — Biden on Wednesday told donors that his campaign has determined that his base is “among the people I grew up with, white working-class, high-school educated people.”

Biden grew up in swing-state Pennsylvania and has headquartered his campaign in Philadelphia.

Ruy Teixeira, a senior fellow at the Center for American Progress who has written extensively about election demographics, said that in the short term Biden may have “settled” the question between those who wanted the party to focus a little more on white voters and a moderate messenger or be more progressive and nonwhite.

Still, Biden manages to blur the debate lines because he won such strong black support, was the heir to Obama’s legacy and, Teixeira said, is now “running on a pretty friggin’ left program when you compare it to Hillary and compare it to Obama and go back a few cycles.”

Teixeira said it’s possible Biden could go in an even more progressive direction by picking Sen. Elizabeth Warren, the primary rival who him last week. But he said it’s more likely that race and region would be bigger factors in Biden’s selection.

“If I had to make a guess, it would either be the Kamala route or the Klobuchar-Whitmer route. It’s pretty much a toss-up in my mind. It does reflect that debate,” Teixeira said, adding that the “center of gravity” leans more toward a black running mate like Harris, Abrams or Florida Rep. Val Demings.

At 77, amid speculation he would only seek to serve one term in the White House, Biden understands the critical role he is poised to play in shaping the party’s identity for years to come.

“I view myself as a bridge, not as anything else,” he said at a Detroit event in early March that featured Harris, among others. “There’s an entire generation of leaders you saw stand behind me. They are the future of this country.”

While he hasn’t tipped his hand on which direction he is leaning, Biden has already had public auditions of sorts, for some of the women on his shortlist. Whitmer was the first guest on his new podcast “Here’s the Deal.” And earlier this month, Harris made a surprise appearance at one of his virtual fundraisers, where she introduced him.

An adviser to Biden noted that he thought highly of three of his former opponents. He appreciated Klobuchar’s hard work to help him win Minnesota, Warren’s attention to detail and policy, and Harris’s dynamic personality and her friendship with his son, Beau, who had passed away in 2015.

“Anyone who is telling you about who’s leading in the so-called ‘veepstakes’ is full of shit and doesn’t know anything,” said the adviser.

Biden’s campaign committee to oversee the vetting process is expected to start by month’s end. The committee is to include campaign co-chair Cedric Richmond — a former Congressional Black Caucus chair — legal counsel Dana Remus and President Obama’s former counsel Bob Bauer, husband of one of Biden’s top advisers, Anita Dunn. Biden’s longtime advisor Ron Klain is also expected to play a role in the discussions.

Neil Sroka, an activist with the progressive Democracy for America group and a city councilman in the Michigan city of Grosse Pointe Farms, said one factor Biden shouldn’t overlook in his calculation is the importance of the progressive base.

“It would be a mistake for him to just focus on how you assemble the Obama coalition. It should be about where the party goes in the future,” Sroka said. “He’s acknowledged he’s not the future of the party. It’s precarious if he picks the wrong future, and that’s going to be a real challenge.”

Michigan’s Democratic Party chair, Lavora Barnes, says she’s conflicted over the choice. Whitmer would be on “everyone’s shortlist for vice president because she is so terrific,” she says, but Barnes doesn’t want Whitmer to leave as Democrats build strength in the state and the governor faces off with Trump over fighting the coronavirus contagion.

Barnes said Biden, who played a big role in the Obama administration’s auto-industry bailout, is so well-known in the state that he’s a “son of Michigan.” As a black woman, she said, she prefers a woman of color on his ticket.

“Having a woman of color would tip the scales,” she said. “If you look at the way this country voted for Joe Biden, he doesn’t have a race issue or a turnout issue. But I do think he can round out his candidacy and make the ticket stronger.”