So, in short, I think that experience, both administrative and political, is a vital requirement for any President.
http://volokh.com/archives/archive_2008_08_31-2008_09_06.shtml#1220574845This article argues that political experience isn't always a good predictor of how well a person will govern. The author asserts:
Nonetheless, there is no systematic evidence suggesting that presidents with extensive prior political experience have done better than those with relatively little.
As an example:
It's easy to think of highly experienced presidents who performed poorly in office. James Buchanan, John Quincy Adams, and Richard Nixon are some of the best examples. On the other hand, several presidents with very little experience have done extremely well. Abraham Lincoln, whose only major elected office before becoming president was a single term in the House, is the most famous case. Among post-World War II presidents, the ones with the most prior political experience were Nixon (vice president for 8 years, prominent congressman), Lyndon Johnson (VP and powerful senate majority leader) and George H.W. Bush (VP for 8 years, various important positions in the executive branch). It's hard to argue that these leaders performed systematically better in office than relatively less-experienced counterparts such as Truman (VP for only a few months and a brief Senate career), Clinton (governor of a small state), and Reagan (governor of California, but very little foreign policy experience). Eisenhower (prominent general, but no experience in elected office), Ford (House minority leader) and Jimmy Carter (governor of a major state; member of the foreign policy-focused Trilateral Commission) fall somewhere in the middle between these two groups.
Many Obama supporters have touted his intelligence as a reason he is a better choice. While I would like a president that is somewhere at the high nd of the spectrum, there is no proof that the being very smart makes you a good leader. Nixon had a good academic record and was lousy. Hoover was very smart, translated a renaissance work that is still used as a text today, and lectured at several prominent universities. I wouldn't argue he was a good leader.