Minnesota Sen. Amy Klobuchar would bolster Biden’s moderate bona fides, project competence, help to ensure that her home state continues to vote blue, and maybe even contribute to the ticket’s strength across the Midwest more broadly. On the other hand, Klobuchar also failed to generate much enthusiasm among voters in her run for the presidency (at least outside of Minnesota, where her endorsement of Biden the day before Super Tuesday paid off handsomely) — and there’s little reason to think she would help the campaign with other demographic groups.
The presidential campaign of New Jersey Sen. Cory Booker went nowhere, despite him being widely liked in the party establishment and by many journalists and pundits. As a charismatic, smart, idealistic, and youthful African American man who works to straddle the party’s neoliberal and more progressive wings, Booker would check a decent number of boxes. Whether checking those specific boxes would add much to a ticket led by the moderate-progressive who served as two-term vice president to the country’s popular first-ever African American president would be an open question.