It's called "The Trudeau Effect," for those old enough to remember. It's named after the late Canadian prime minister, Pierre Elliott Trudeau, a hip and charismatic figure whose popularity increased in direct proportion with the square of his distance from Ottawa. In other words, the rest of the world loved him, while Canadians used a variety of epithets (and in the case of French Canadians--gestures) to describe him. Not that Obama has reached this extreme yet, but you can bet he eventually will if he becomes President.
So our Golden Boy has returned from abroad, and his feet must now, once again, touch the ground. No more soaring visions, no more paeans to the Unity of Man. He's gotta talk about national defense, pump prices, foreclosures, job outsourcing, education money, and all the other humdrum stuff that average Americans base their voting decisions upon. If you don't get mud on your boots, you can't reach for the stars.