James Fallows on the 2008 presidential primary debates, in The Atlantic:

When politicians do try to lay out a new thought or policy, they tend to do so from the safety of incumbency, rather than as part of a campaign. For instance: when Carter ran for office, he talked about the importance of human rights around the world. But not until six months into his presidency, in a commencement speech at Notre Dame, did he explain in the fullest sense how the United States could balance an emphasis on human rights with awareness of its practical interests and obligations. It is a speech that survives re-reading 30 years later. (I am biased, having been involved, but Jerome Doolittle was the main writer.) Nothing from [Obama’s] campaign does so. I expect some of the addresses Obama has already given will, whether he is elected or not.