With a resume of political posts, including two stints as budget director and most recently as Chief of Staff, it is simply difficult to look at Lew experience and find that reassurance.
(Read more: In Picking Lew, Obama Turns a Page at Treasury)
To be sure, that independence can end up being either a liability or worthless. John Snow, who held a Ph.D. in economics and headed CSX, was religious in his advocacy of administration policy and almost never offered an opinion at odds with the White House, even while many argued that tax cuts amid war would result in large deficits.
Paul O'Neill, despite excellent intentions, found his executive experience in the private sector a liability in his efforts to run Treasury more like a business. For any Treasury Secretary, being either at odds with the White House on any substantial issue is fatal. Whatever Geithner thought of Obama's policies, he publicly supported every one of them. (He even ended up backing the Volcker Rule despite initial opposition.)
All government bodies are in some way political. Most appointees are politically appointed and many of the top ones must be approved by Congress. But there is a spectrum of, for lack of a better word, politicalness. Although both have recently been criticized, the Supreme Court followed by the Federal Reserve probably enjoy the best reputations for independence.
If you were placing agencies on a line with the Supreme Court on one end and the White House on the other, the Treasury Department would best be put closer to the White House but not as close, say, as the Departments of Defense or Education. That is to say, there has always been a certain measure of political independence attached to the Treasury.
Why? Because the Treasury has responsibilities that transcend strict political considerations. The Treasury heads the Internal Revenue Service and is responsible for the apolitical collection of taxes. It is charged with issuing and managing the national debt, which creates a responsibility to both the White House (fund it cheaply) but also to markets (fund it predictably.) The Treasury Secretary is the chief spokesman on the dollar and represents the United State in its international economic relations. It's a small example, but Geithner was always careful not to give press interviews or speeches during market hours — understanding he had a responsibility to markets in his public pronouncements.
In an editorial on Thursday, The Wall Street Journal suggested markets would be losers in the selection of Lew. Whether that's the case, it seems the White House is leaving something on the table too.