There will likely be months of debate over who presumptive Democratic nominee Joe Biden should pick as his running mate — and what criteria he should use in making that decision.

We already know one such criterion: Biden has pledged to choose a woman. But what else is he looking for in a vice presidential nominee?

One view of the vice presidential selection process, often expressed by people who themselves work for campaigns, is that the presidential nominee is making a personal choice, opting for someone whom he or she connects with and feels would be a strong partner in governing. Another view, according to research we (Adler and Azari) have done, is that the vice presidential choice often reflects broader dynamics in the party. In this view the nominee often chooses a running mate who connects with some broader goal of the party or who helps appeal to some faction or ideological bloc in the party that is not well represented by the candidate at the top of the ticket.

It’s really hard for us to establish whether Biden enjoys chatting more with Sen. Kamala Harris or Sen. Amy Klobuchar, so we’re going to take a party-centered approach to this question. We can look at the Democratic Party and some of its goals and use those as a rubric to evaluate some of Biden’s potential running mates. We have focused here on women who are either governors or senators — the traditional resumes of a vice presidential pick — but have also included a few noteworthy figures who don’t hold statewide office.

Goal 1: Help with electability, real or imagined

Helps: Sen. Tammy Baldwin of Wisconsin, Sen. Amy Klobuchar of Minnesota, Michigan Gov. Gretchen Whitmer

Hurts: Sen. Elizabeth Warren of Massachusetts

Beating President Trump is almost certainly the Democratic Party’s main goal at the moment. So which potential running mates would make the Democratic ticket more electable?

Let’s talk about actual, factual electability first — that is, helping Biden defeat Trump by bringing voters to his coalition who wouldn’t otherwise be there. The electoral effects of vice presidential choices are somewhat complicated to study because the sample size is so small — we’ve had only 18 presidential elections since the end of World War II.

The broad consensus among scholars is that the electoral effect of running mates is not clear and obvious — and probably somewhat modest. In other words, we should not assume that choosing Harris or former Georgia House Minority Leader Stacey Abrams would boost Biden with black voters, that Baldwin, Klobuchar or Whitmer would attract voters in the Midwest, or that Sen. Catherine Cortez Masto would help in Nevada. Nor should we assume that any of these female politicians would particularly connect with female voters. For example, in their upcoming book, “Do Running Mates Matter?,” political scientists Christopher J. Devine and Kyle C. Kopko downplay a lot of the electoral effects of running mates, based on their research. They argue that there is little evidence that picking a person from a particular region helps in that region or that choosing a person from a demographic group helps with voters in that demographic. They also reject the idea that running mates boost the tickets in their home states, a conclusion other scholars and experts have reached as well.

Other academics are slightly more bullish on running mates’ potential electoral impact. Historically, vice presidential picks have boosted the ticket by 2-3 percentage points in their home states according to political scientists Boris Heersink and Brenton D. Peterson. Some scholars have found that Republican Catholics are less likely to vote for the GOP ticket if the Democratic running mate is Catholic and that in 2008 then-Alaska Gov. Sarah Palin boosted turnout among fellow conservatives. Devine and Kopko themselves argue that vice presidential choices matter because they can affect how voters see the presidential nominee in ways that sometimes have electoral effects. According to their research, Sen. John McCain’s selection of Palin as his running mate caused a rise in negative views of McCain because of voters’ perception that Palin was unqualified for the position.

“Any time you talk about a running mate winning votes, you’re really talking about voters choosing a suboptimal president in order to elect their preferred vice president; otherwise, the running mate didn’t actually change votes but just reinforced a preexisting preference. So, suffice it to say, we’re pretty skeptical that such effects will occur very often or to a significant degree,” Devine told us in an email message.

He added, “By choosing a woman — or, say, an African-American woman, in particular — Biden … would be sending a message to voters about who he is — specifically, that he is someone who values diversity and the role that women — or African American women, in particular — play in American society and in the Democratic Party. That message probably would help to win him some votes. But we’re not exactly talking about ‘delivering’ large blocs of voters.”

So let’s say the electoral impact of vice presidential choices is complicated. Here’s what’s not in dispute: Party elites, presidential campaign advisers and sometimes presidential nominees themselves often believe that vice presidential candidates will have an outsize electoral impact, whatever the reality is. For example, according to his memoirs, McCain felt that Palin might attract moderate Democrats who voted for Hillary Clinton over Barack Obama in the 2008 Democratic primary.

So who do party elites think is the best vice presidential nominee to help Biden electorally? They consistently said that Warren was weak on electability when she was running for president, so this metric won’t help her cause.

Abrams has an electability perception problem too. She is nothing like Palin, but Democratic elites we have talked to are wary that voters won’t like pairing someone who has never held an elective office higher than state representative with a 77-year-old presidential nominee. A wide body of research suggests that presidential nominees generally pick a running mate who has a lot of political experience, usually at the national level, likely to address concerns about whether the running mate is ready to be president if necessary.

Party elites tend to indicate that the Democrats’ path to victory is winning white voters in the Midwest — as opposed to firing up more liberal voters or increasing support among people of color. So this metric (party elites’ perceptions of electability) would likely favor Baldwin, Klobuchar and Whitmer in particular.

Goal 2: Balance the ticket demographically — particularly on race and ethnicity

Helps: Sen. Tammy Duckworth of Illinois, Sen. Kamala Harris of California, New Mexico Gov. Michelle Lujan Grisham, Abrams, Cortez Masto

Hurts: Baldwin, Klobuchar, Warren, Whitmer … basically anyone who is white

Close to 40 percent of registered Democratic voters identify as Asian, black, Hispanic or something other than white. And the Democratic Party cares deeply about racial diversity. An all-white ticket might happen, but it would get lots of blowback. The same is likely true of an all-male ticket — hence, Biden’s pledge. Already, House Majority Whip James Clyburn, whose endorsement of Biden seemed to help the former vice president win big in South Carolina, is calling for him to name a black woman as his running mate.

This kind of demographic balancing has occurred in the past two Democratic primaries. The major contenders to be Obama’s running mate in 2008 were all white men, and the top contenders to be Clinton’s running mate in 2016 were nearly all men.

Currently, only one woman of color is a governor (Lujan Grisham), and only four are U.S. senators (Hawaii’s Mazie Hirono, Cortez Masto, Duckworth, Harris). So it’s likely that Cortez Masto, Duckworth, Harris and Lujan Grisham all will get a serious look from Biden and his team and that they will also consider more nontraditional choices, like Abrams and U.S. Rep Val Demings of Florida, in part to meet the party’s demand for a racially diverse ticket. (Hirono will turn 73 on Election Day, and we doubt Biden would pick a running mate who’s nearly his age.)

Goal 3: Balance the ticket ideologically

Helps: Abrams, Harris, Warren

Hurts: Klobuchar

The other main balancing goal that presidential nominees typically have, in addition to demographics, is ideology. In 1988, the Democratic nominee, Gov. Michael Dukakis, sought to counteract his reputation as a Massachusetts liberal by choosing one of the party’s more moderate figures, then-Sen. Lloyd Bentsen of Texas. In 2012, the GOP nominee, former Massachusetts Gov. Mitt Romney, considered insufficiently conservative by some Republicans, chose as his running mate someone beloved by the GOP’s right wing: then-Rep. Paul Ryan of Wisconsin.

By this metric, Klobuchar would not be an ideal running mate for Biden. She has a somewhat centrist record, as does he, and took fairly similar positions to the former vice president during the Democratic primary, such as panning the idea of Medicare for All. Choosing her as his running mate would intensify the criticism of Biden from the party’s left wing, who would likely complain that he is expecting liberals to vote for him while essentially ignoring their wishes.

Warren, of course, is firmly on the left. Harris is pretty left, based on her voting record in the Senate. But as California’s attorney general from 2011 to 2017, Harris took some conservative stances and as a 2020 presidential candidate didn’t embrace Sen. Bernie Sanders’s Medicare for All approach or a wealth tax. Abrams hasn’t taken Sanders-style stances on economic issues, but she is well known for her work on voting rights issues, which might lead to her being perceived by voters and activists as being left. Also, some political science research suggests that black candidates are often perceived to be more liberal than they actually are. In other words, if Biden picks Abrams or Harris, he could both appease some on the left and not annoy more centrist people in the party who may not like Warren.

Goal 4: Help Democrats gain a Senate majority

Helps: Duckworth, Harris

Hurts: Baldwin, Warren

This is a newer factor, without a lot of historical precedent in either party. But control of the U.S. Senate is in play in 2020. And if the Republicans retain the most of the seats, Senate Majority Leader Mitch McConnell could block much of what a new Democratic president tries to do, just as the Kentucky Republican limited Obama while he was in office. For this reason, some Democratic activists are wary of picking a sitting Democratic senator for the vice presidency if there is any possibility that person will be replaced by a Republican.

If Duckworth or Harris became vice president, the Democratic governors of their respective states would pick their replacements, who would serve until a special election is held in 2022. Democrats would be favored to keep those Senate seats because Illinois and California lean heavily Democratic. Minnesota (Klobuchar) and Nevada (Cortez-Masto) also have Democratic governors who would appoint a replacement through 2022, but they are more swing-y states, so Democrats could eventually lose those seats in 2022. In Massachusetts (Warren) and Wisconsin (Baldwin), there would be a special election in 2021. The incumbent in the Bay State would likely be a Republican since GOP governor Charlie Baker would pick the person. (Democrats in Massachusetts do have some potential workarounds, however.) This dynamic is a real problem for Baldwin, though, since Republicans might be slightly favored in a special election in Wisconsin.

This is an informal list of criteria. You could certainly include other measures — ours are not necessarily exhaustive or even the best measures. But the history of vice presidential selections suggests that the process is not dominated by questions that perhaps should matter the most, such as:

Is this person best qualified to run the nation if the president cannot finish his term in office?

Is this person a great manager who can help lead the executive branch of the government?

Is this person well versed in policy?

Is this person the best choice to become the next-in-line presidential candidate for the party?

Perhaps Biden’s considerations will change as a result of the novel coronavirus, which means the next president could enter office with a true national crisis on his hands. But we’re skeptical that the vice presidential selection will be much different than in the past.

In any case, looking at the party-based criteria, here’s how things shake out for Abrams, Harris, Klobuchar and Warren, who The New York Times recently reported are senior Democratic Party officials’ leading choices for Biden’s running mate. (We’ve also included Duckworth, who’s a more obscure senator than Warren, but we wanted to note how favorably she looks compared with her in terms of these party-based metrics):

Harris: three positives, no negatives. Abrams: two positives, no negatives. Duckworth: two positives, no negatives. Klobuchar: one positive, two negatives. Warren: one positive, three negatives.

You might be thinking, “Harris was a dud as a presidential candidate,” but often that doesn’t matter. And as with George H.W. Bush, Al Gore, Dick Cheney and Biden, the person who gets elected vice president is often someone who at some point flirted with a presidential run or actually ran for the top of the ticket and lost. What this exercise suggests is that Harris fits the party’s goals fairly well for a running mate alongside Biden — she’s to the left of him ideologically, she’s not white, the party won’t lose a Senate seat if she becomes vice president, and some people in the party will assume she helps with electablity by appealing to black voters in particular. We’re not predicting that Biden will pick her — he might decide that perceived electability trumps everything else and go with Klobuchar or Whitmer or another Midwestern white woman. He might decide that Warren’s policy chops are particularly useful in the midst of a crisis like the coronavirus pandemic and that placating the party’s left wing is important for symbolic and electoral reasons. But Biden is a party man, and Harris is a party choice.





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