Chad Mitchell had a lot to do with migrating strong social and political themes onto pop radio.
They gave voice to great songwriters, and prepared us to receive the works of those with "less than perfect voices".
PP&M did that for Dylan, CMT did it for scores of others.
One hell of an acheivement, I'd say. Their importance in getting exposure for stuff that ought to be heard has been greatly undervalued.
CM, whereever you are, I'm in your debt.