Drafting a completely new constitution is highly unlikely because the United States and its individual states like to boast the fact that they have one constitution that they keep updating instead of writing a new one when the need deems it. Basically, constitutions are written according to what the spirit of the age is. In the future it will change because the people's behavior and understanding of the world will change. One day maybe prohibition comes back or people lose the right to vote or anything similar. Nobody knows what might happen because nobody knows what lies in the future.
