The United Church of Christ and the Southern Baptists allow each congregation to have a great deal of authority, including who to hire as pastor and what credentials the person must have to be the minister. This approach to religious organizational polity is called

Ecclesiastical Polity

Explanation:

Ecclesiastical polity is the operational and governance structure of a church or of a Christian denomination. It also denotes the ministerial structure of a church and the authority relationships between churches. Polity relates closely to ecclesiology, the study of doctrine and theology relating to church organization.

source: Wikipedia