There’s one more way to think about qualifications, though: Who can best champion the department? This is the strongest case for Buttigieg. DOT is not always a high-profile department, though it touches Americans’ lives pretty much every day, and his presence will elevate it. Because he is a slick communicator, he will be able to advocate for it publicly, and because he was a notable surrogate for Biden during the election, he’ll be able to get the president’s attention. (Plus he’ll be dealing with trains, a subject beloved by Biden.) There’s a similar rationale for Xavier Becerra, Biden’s choice for Health and Human Services, who has a limited health-care résumé but has been deeply involved in litigation over the Affordable Care Act, knows Washington well, and has a profile that may elevate an otherwise-sometimes-ignored department.

The most productive way to think about Biden’s selection of Buttigieg, as well as other secretaries, is as a whole: What kind of Cabinet is the president-elect trying to assemble? There doesn’t seem to be a unifying theme. In some cases, he seems to be choosing for generic leadership skills rather than subject expertise. In others, he’s picking people he trusts. In still others, he’s picking people to discharge favors he owes, either to individuals or to demographic groups.