How was this simple creole priest able to inspire the people he served into a rebellion against the Spanish-born peninsulares, which would eventually lead to a free Mexico 11 years later?

Father Miguel Hidalgo saw the rule of the peninsulares as a rigid class system meant to keep those deemed unworthy down. Criollos (people having a parent of Spanish blood and parent of Native blood) and Natives (both parents having native blood) were the majority and yet they held little to no power. Father Hidalgo, as well as many others, were tired of the constant parade of new peninsulares coming over the New Spain (Mexico) to line their pockets instead of caring for the people and trying to make the country better.