In any event, the promises were so grand, the moment so inspiring, that the aftermath had to disappoint.

Seemingly simple campaign pledges turn out to be intractable problems. Closing Guantanamo and ending “don’t ask, don’t tell” are easier to proclaim than achieve. This is no surprise to anyone who took the time to wonder how, exactly, these would be accomplished. But campaigns worry about election first, implementation later.

Clear positions yield to political realities. Having Medicare negotiate prescription drug prices gives way to the need to get drug companies on board. The campaign climate-change plan to auction off all emissions permits morphs, without a presidential peep, into a House-passed measure that would hand out 85 percent of the permits as political candy to mollify lawmakers in districts that would be hit hard by strict emissions limits…

Which leads to the core question facing the still-young administration: What happens when people start to wonder whether they can really believe in this change?