Whoever Biden chooses will be elevated to a prominent role in the Democratic party and in the political life of the country. Biden himself must be aware that, had Barack Obama not picked him for his 2008 ticket, his chances of being his party's likely 2020 nominee would have been slim.
Perhaps more importantly, vice presidential choices matter because they help frame perceptions of the presidential candidate. When Donald Trump chose Indiana Gov. Mike Pence as his running mate in 2016, it signaled both that Trump was willing to work with conventional career politicians and that he cared about the conservative base of the Republican Party.
One of the most intriguing examples of a nominee contributing to the narrative around a presidential campaign occurred in 1992 when Bill Clinton, the Arkansas governor who represented the southern moderate-to-conservative wing of the Democratic Party, did not balance his ticket with a northern liberal, a woman or person of color, but reinforced his image by choosing Tennessee Sen. Al Gore who, at the time, was also part of the party's southern moderates. This helped Clinton portray himself as a centrist breaking from a party that many swing voters saw as becoming too liberal.
However, this year will be different for Biden. Given his age -- he will be 78 on Inauguration Day of 2021 (Trump will be 74) -- and the reality of a terrible pandemic that preys on older people, Biden must emphasize governance when choosing a running mate. Whoever Biden chooses, should he be nominated, must be seen by voters as able to be president immediately if something were to happen to him.
This may be bad news for Abrams, but it should be encouraging for several other women, including California's Kamala Harris, Massachusetts' Elizabeth Warren and Minnesota's Amy Klobuchar. These three senators competed with Biden for the Democratic nomination but fell behind him, and Vermont Sen. Bernie Sanders, early in the campaign season. However, they are all clearly qualified to be president right now. Harris was California's attorney general for six years and has served three and a half years in the US Senate. Warren was elected to the Senate in 2012 and was in national government for years before that. Klobuchar won her Senate seat in 2006.
However, it would send a very different message to white working-class voters. Putting a white Midwestern woman like Klobuchar on the ticket would send a message from Biden that white working-class voters are the key to his coalition while downplaying the importance of African American voters.
Klobuchar represents a swing state, so her ability to deliver that state in the general election may figure into Biden's deliberation as well. (Warren and Harris both represent solidly Democratic states that will vote for Biden no matter who his running mate is.) Other swing-state politicians who would also be ready to take on presidential responsibilities immediately if necessary include Wisconsin Sen. Tammy Baldwin, currently serving her second term in the Senate, and Michigan Gov. Gretchen Whitmer.
It remains true that for the huge majority of Americans, Biden's choice will have little impact on their vote. Most decided long ago whether or not they want to give Trump another term. However, close presidential elections are won on the margins as undecided voters in a handful of states make up their minds. For those voters, the image and story that the candidates craft are very important -- and for Biden part of that story will be told through his choice of running mate.