Final answer:
William Berkeley was supported by the Anglican colonists in Virginia who were loyal to the Stuart monarchy and favored traditional order, opposing religious and political changes.
Step-by-step explanation:
The group that supported William Berkeley was predominantly the Anglican colonists in Virginia who remained loyal to the Stuart monarchy during the English Civil War. As a Royal Governor of Virginia, Berkeley favored the established Anglican Church and its practices, opposing the spread of Puritanism within his colony. His support base did not welcome the Puritans and even found their presence distasteful, as Berkeley's governance and the Anglican colonists' loyalty were both firmly rooted in the Stuart monarchy.
This alignment led to oppressive measures against nonconformists, such as Puritans, further solidifying Berkeley's support among Anglicans who desired to maintain traditional order and resist religious and political changes.