Dr Rohmer in this novel is a very important character because it is he who is the district superintendent for Clarion County and it is also he who is the Commissioner of Education of New York State. Thus he is involved in the triumph of The Souls and their rise to public prominence, as their success reflects well on him. Note how in Chapter 9 he is described as being very happy to profit from the success of The Souls:

That started the blitz of publicity to which Dr. Roy Clayton Rohmer happily surrendered. He hungered for "positive taxpayer feedback," so he called a press conference...

Dr Rohmer therefore is a character who is involved with The Souls because of his function and job role, and he is also a character who is shown to be happy to use the success of The Souls to gain more fame for himself and increase his own public standing. He is only a minor character in the book as a whole but one whose actions reveal a somewhat cynical attitude towards those in positions of influence and governance.