The Daily Show noted that both sides are pretty hypocritical on this exact issue.
What it comes down to for me was content. It was such a condescending letter, joke or not. Sending such a letter to the leaders in Iran (most of home were educated in the west) talking as if they are greatly ignorant of our most basic government setup (really? You need to explain how a President is only president for four to eight years?!) is just bad form. It looks pathetic and it sure does not make our government look good.
It is almost like Republicans hate America so much, they will do anything to bring her down a notch.
I need to believe that, because the only other logical reason Republicans did this douche move is that they are such monumental idiots, they are unworthy of office…and that is just to scary a thought.