John Hall had also held prior elected office.
I personally have no problem with anybody running for office no matter what their background if they can show their knowledge of the issues and understanding of how the political process works. John Hall showed that with his awareness of various causes especially on the environment as well as his work in the elected offices he held prior to being elected to Congress.
Kid Rock has to overcome his own prior statements that entertainers should keep their political opinions to themselves.
Beyond that, I don't know much about him, other than he strikes me as the sort of wealthy, out of touch elitist that working class Republicans claim they dislike.