In what way would it be unconstitutional?
As far as I can tell, the word “peer” does not appear anywhere in The Constitution of the United States.
if you read up on what is meant by an impartial jury, the concept of a jury of your peers is inherent in this idea, because part of the impartiality comes from people being able to put themselves in the others’ position and thus determine things like what is or isn’t ‘reasonable’ and ‘beyond reasonable’.