Hillary Clinton selected Sen. Tim Kaine as her running mate to boost her prospects in his home state of Virginia and to put a moderate white male on the ticket. Although Clinton was victorious in Virginia, her choice of the nondescript Kaine did nothing to unify Democrats after her long, bruising primary battle with Bernie Sanders. Joe Biden is now faced with the nominee’s quadrennial task of selecting a partner for the general election. He should not repeat Clinton’s mistake. 

The selection of a running mate is the one free move that a nominee gets in the general election campaign — their one chance to compensate for a gap in their resume or address a weakness in their coalition. The problem most nominees face is there are typically multiple gaps that need attention and no single choice that can address them all. Running mates can be counted on to give the nominee a small boost of a point or two in their home state, which matters if, like Virginia in 2016, the state is highly contested and critically important to the nominee’s electoral math. They can add regional, age, ideological, gender or racial balance to a ticket. They can energize a wing of the party that was unsuccessful in the primaries. They can bring buzz and excitement to a campaign. They can bring experience that the nominee lacks.

But they can’t do it all.

Past nominees have used their pick to check one or two of these boxes. John F. Kennedy and Michael Dukakis of Massachusetts both ran with Texans to bring regional balance to their tickets. A portion of Joe Biden’s appeal to Barack Obama was his popularity with white working class voters. Ronald Reagan teamed up with his vanquished rival George W. Bush to unify the Republican Party following a heated primary contest. John McCain plucked Sarah Palin from obscurity to appease conservatives, bring gender balance to his ticket, and generate excitement (which she did, although more than McCain bargained for).

Like these nominees before him, Biden has several gaps to fill. Having already pledged to run with a woman, he now has to figure out what else he wants to accomplish with his selection. In the coming weeks, there will be a lot of speculation about his choice but it really boils down to what Biden believes is the most effective way to get to 270 electoral votes: Should he try to strengthen his position with moderate voters in key midwestern swing states or try to win over reluctant supporters of Bernie Sanders and unify the party?

If he is looking for a midwestern running mate with appeal to white working class voters, Amy Klobuchar is the most recognizable name on a list that also includes Michigan Gov. Gretchen Whitmer, who has received some national attention for her response to the pandemic. Klobuchar has been the subject of a lot of speculation (which, like all speculation surrounding every vice presidential pick, is largely uninformed), but she would bring less to the table than other possible choices given her limited appeal to progressive voters. Klobuchar would be the Tim Kaine of 2020 — a fellow moderate whose strengths duplicate but do not enhance the strengths of the standard bearer and who does little to reach out to disenchanted elements of the party. 

This is where a recent large-N survey of Michigan and Wisconsin Democrats and independents conducted for the group Donors of Color could be instructive, because it suggests there may be options that appeal to base voters while also boosting Biden’s position in the Midwest. Contrary to conventional wisdom, the survey does not rank Klobuchar as the top preference among voters Biden will need to attract in these midwestern states. Elizabeth Warren tops the list in Wisconsin and is second in Michigan only to native daughter Whitmer (who finishes a distant fifth in Wisconsin where she is less well known). Among voters of color in these states, the top choice is Stacey Abrams, who fell just short of being elected Georgia governor in 2018 in a contest marked by widespread voter disenfranchisement. Abrams also places well ahead of Kamala Harris among black voters, while Warren receives the most consistent support among all respondents in both states. The other names tested — Illinois Sen. Tammy Duckworth, Nevada Sen. Catherine Cortez Masto, and Florida Rep. Val Demings, have lower name recognition and do not poll as well.

Either Warren or Abrams would tap into the intellectual energy and enthusiasm that defined the primary season. Either would galvanize the base, bring vitality to the Biden campaign, and help unify the party. But the survey’s most interesting finding is the prospect that either one could also help Biden in key midwestern battlegrounds by prompting Democrats to turn out, suggesting that unifying the party does not have to be at odds with strengthening Biden’s electoral position in swing states. If Biden has innate appeal to white working class voters who supported Obama then defected to Trump — which, after all, is the fundamental claim of his candidacy — then he should have the luxury to select a running mate who can drive turnout among that large share of the party that remains lukewarm to him. With 2020 likely to be decided more on turnout than persuasion, Warren or Abrams can be helpful in the Midwest and across the country. 

Like any potential running mate, Warren and Abrams have their liabilities. Although she projects youthful energy, Warren at 70 would mean an all-septuagenarian ticket. Even though she could potentially appeal to suburban women who were key to the Democrats’ success in 2018, she comes from a state that Biden is already certain to win, with a Republican governor who would appoint her senate replacement (at least until a quick special election could be held). And while she would bring a knowledge of economics that could prove tremendously valuable as the economy sinks into quicksand, she would not bring the racial diversity that could be important to a lot of Democratic voters. As for Abrams, whose strength relative to the better-known Harris among African American Democrats suggests the potential for broad electoral appeal, her lack of governing experience in a high-level elected office could be a hindrance for voters looking for someone ready to step in should something happen to a nominee who would become the oldest inaugurated president. 

It is very easy to get caught up in the vice presidential sweepstakes and overstate the importance of a running mate. Presidential candidates have been able to survive odd or unhelpful choices (Dan Quayle, anyone?), and in the end, people vote for the top of the ticket. But the choice of a running mate makes a loud statement about the nominee’s priorities. After acknowledging the need to earn the trust of Bernie Sanders’ supporters, Joe Biden has the opportunity to demonstrate he is worthy of that trust by running with someone progressives can embrace. In so doing, he could avoid making the mistake that Clinton made by following conventional wisdom and going small. And because it’s possible for Biden to find a running mate who could unify the base and strengthen his electoral position, it would be good politics as well.