First of all, the fact that someone running for office has no political experience is not a bad thing and was what the original premise of government in the U.S. was based on. Citizens taking time out from their profession to serve in government for a term or two. Career politicians that remain in office their whole lives and have no other real life experience is what has gotten us to this sad state of affairs.
Having said that, the consideration to have John Mellencamp run for office just reaffirms what politics in the U.S. has become today...a popularity contest.