With the announcement that Tom Vilsack, the former governor of Iowa, will be nominated to be Secretary of Agriculture and that Colorado Senator Ken Salazar will be nominated to be Secretary of the Interior, six of the fifteen cabinet departments are likely be headed by individuals who have reached the top rungs of electoral politics by serving either as governor or senator (the others in this category are, of course, Hillary Clinton, Tom Daschle, Janet Napolitano, and Bill Richardson). This seemed like a large number to me, so I thought it would be worthwhile to compare to recent presidents. For comparability purposes, I’ll focus only on the first appointments to each position.

George Bush’s initial cabinet had only three former governors or senators — John Ashcroft (Gov & Sen, MO), Tommy Thompson (Gov, WI), and Spencer Abraham (Sen, MI) — in the 14 departments that existed when he came to office. Former Pennsylvania governor Tom Ridge was added when Homeland Security was created.

Bill Clinton also appointed three high-flying politicians to his cabinet — Lloyd Bentsen (Sen, TX), Richard Riley (Gov, SC), Bruce Babbitt (Gov-AZ) — while George H.W. Bush held over Dick Thornburgh (Gov, PA) from the end of the Reagan administration but didn’t appoint any of his own. Ronald Reagan appointed Richard Schweiker (Sen-PA) and James Edwards (Gov-SC) to head departments he didn’t care much for (HHS and Energy).

So six is a big number. Moreover, big-name politicians will be running many of the departments that will be crucial in developing and implementing President Obama’s agenda and may determine the success of his presidency (e.g. State, Health and Human Services, Homeland Security).

So what are the pros and cons of so many politicians in the cabinet? One argument in favor is that cabinet appointments are useful for building and maintaining coalitions and avoiding party factionalism. This may explain the Clinton appointment, but it is not so obvious that this can account for the others most of whom supported Obama in the primaries. It is also curious as to why avoiding party factionalism is so much more important to Obama than it was for the other presidents of the past 30 years. The second benefit is that senators and governors bring strong ties to Congress and the states. Legislative relations will be obviously important to Obama as he tries to ensure that the “most liberal Congress in history” does not get too far out in front of him. Harmony with the states will be crucial on health care, the environment, and a host of other issues.

But politicians in the cabinet create problems as well. Unlike the career civil servant who ascends to the position or the Washington newcomer, former senators and governors have power bases and networks that are independent of the White House. So it will be considerably harder for the administration to control and manage what happens in the agencies. Second, senators and governors are usually generalists without deep expertise about the policy jurisdiction or culture of the departments that they are to lead. Such a lack of expertise may lead to policy failures or to capture by careerists or both. My former colleague David Lewis has produced ample evidence that careerists do a much better job running sub-cabinet agencies than do political appointees. It would be troubling indeed if his findings were to apply to cabinet departments as well.