Well, I don't know "most people who criticize Obama's decision to go to Copenhagen" so I won't generalize. Moreover it seems to me that you are making precisely the same prejudgement of my motives of which you seem to accuse me with respect to the president.
In fact I didn't criticize or attempt to guess his motives. Instead I noted that this was an inauspicious year for the first ever direct appeal by a U. S. President to the IOC on this matter, and the political calculus - both for himself and the nation - should have led him to make a different choice.
This was knowable before the announcement of his trip. My first reaction to learning of his trip was surprise that he would do such a thing and a degree of continuing discomfort with the evident presumption among his admirers and some of the media that the intervention of his star quality will again produce magical results. (That it doesn't quite meet their exaggerated expectations is becoming increasingly evident.)
There is nearly always a U.S. city in the finals for the Olympic games. Since 1990 U.S. cities have hosted have hosted two of the last twelve olympic events (winter & summer) - that's well above average by any rational count.
Now that the threat of the former Soviet Empire is gone, the impression of an unchallenged superpower changes what may have once been widespread support to unease and resentment for the unchallenged elephant in the room. We both know that circumstance is changing, but the psychology of it is an observable fact in the contemporary world, and this is something particularly refelcted in things like the Olympics.
Given its rapid ascent to prominence in the world and its unique combination of political and economic success on its continent, the moment was predictably ripe for Brazil. Moreover president da Silva has rather successfully positioned himself and his country as an admired symbol for emerging nations from what was once called the "third world".
The spectacle of the fall of the Former governor of Illinois and all the attendant reminders of a truly unusual level of political venality there didn't help either.
I doubt very much that, had our president seen the situation this way he would have chosen to make the trip. That he didn't. makes me wonder about his judgement. Earlier I suggested that this was somewhat like a lawyer with a weak case anf the prospect of encountering a hostile jury deciding to go to trial anway - an error of judgement. I believe the analogy is apt, and that its applicability was fairly obvious before the IOC result was known.